A rise and fall of a Chaghadaid community: demographic growth and crisis in ‘late-medieval’ Semirech'ye (Zhetysu), circa 1248–1345

Abstract This article analyses long-term population dynamics—growth, decline, sex- and age-composition—in Chaghadaid-era Central Asia in the context of the ‘Late-medieval Crisis’. It is based on a unique dataset of 630 epitaphs from two East Syriac (‘Nestorian') graveyards in the Semirech'ye region (Northwest Tian Shan, North Kyrgyzstan), boosted by archaeological and osteological evidence from the same graveyards. This epigraphic corpus is truly unique in the sense that this is the only surviving data that allow the undertaking of such a quantitative reconstruction of pre-modern Central Asian demography. A close analysis of the corpus, based on the ‘excess mortality’ method, reveals rapid demographic growth between circa 1270 and 1330, despite frequent short-term mortality crises, caused, most likely, by a combination of environmental and political factors. The population growth came to a sudden halt because of a major plague outbreak in 1338–1339, killing about three-quarters of the local population, and initiating what was known as the Black Death of 1347–1353 in West Eurasia and North Africa. The analysis of sex and age ratios indicates that the local population regime was heavily male-dominated. The plague of 1338–1339 targeted primarily younger women, most likely due to pregnancy-related hazards; conversely, in other crisis years, adult males were more susceptible. The findings of the article are wrapped into the wider context of the ‘Late-medieval Crisis’.

pre-nineteenth-century Central Asia. In reconstructing these trends, I will be deploying the 'excess mortality' method, based on annual counts of erected tombstones for the entire period. To appreciate this long-term population growth and decline of Semirech'ye East Syriac community, the analysis will be placed within the wider environmental, socio-economic, and political context of late thirteenth-and early-fourteenth century Mongol-controlled Central Asia, on the one hand, and within comparative contexts of similar demographic crises in West Eurasia, on the other. In particular, I will discuss the demographic trends of the East Syriac community in the context of the late-medieval (or, the 'Long Fourteenth Century') Crisis. As such, this study has the potential to not only shed a unique light on the demographic history of 'late-medieval' Central Asia (albeit via the prism of just one community), but also to contribute to our wider appreciation of mortality crises in a comparative Eurasian-wide perspective, and the awareness of the importance and impact of the fourteenth-century crisis as a Eurasian, rather than a traditionally European, phenomenon. 12 The Semirech'ye burials database The core material consists of a corpus of 630 tombstones, recovered from two East Syriac cemeteries in northern Kyrgyzstan, in the course of three excavation seasons in 1885, 1886, and 1892, led by Nikolai N. Pantusov  and his assistant A. M. Fetisov. One cemetery is situated outside of Kara-Djigach village, about 11 km to the southeast of Bishkek city centre (henceforth, the 'Kara-Djigach cemetery'), just to the north of the Kyrgyz Ala-Too Range (formerly, the Alexandrian Range) of the Northern Tian Shan mountains; its approximate coordinates are N42°48 ′ 21.68 ′′ E74°41 ′ 8.77 ′′ . The Kara-Djigach cemetery was discovered accidentally by V. A. Andreyev, a local surveyor, in June 1885. 13 The other cemetery is located about 1.5 km to the south of Burana, 10 km south of Tokmok (henceforth, the 'Burana cemetery'; approximately N42°4 2 ′ 59.95 ′′ E75°14 ′ 34.88 ′′ ) ( Figure 1). The Burana cemetery was spotted and initially explored by a local resident and medicine practitioner, Dr F. V. Poyarkov, in October 1885. 14 The cemeteries differed in size, with the Kara-Djigach cemetery by far the larger of the two, occupying about 32,780 square metres (about 256 x 128m); Fetisov and Pantusov estimated the cemetery to have contained about 3,000 burials. Conversely, the Burana cemetery was much smaller in size, housing no more than 100 graves.
The three seasons in which the archaeological works were conducted were: (1) October 1885 (supervised by Fetisov in Kara-Djigach and by Poyarkov in Burana); (2) August-September 1886 (supervised by Pantusov and Fetisov in Kara-Djigach and by Fetisov in Burana); and (3) September-October 1892 (both sites co-supervised by Pantusov and Fetisov). The progress of the excavations as well as the contents of each grave were meticulously recorded by Pantusov and Fetisov in their field diaries, while Poyarkov's report was published by Nikolai M. Yadrintsev, a St Petersburg-based explorer. 15 In the course of these 1885 and 1886 seasons, a total of 134 graves containing 144 skeletons were excavated. Of these, 85 graves with 94 skeletons were dug in Kara-Djigach (two graves with four skeletons in 1885 and the rest in 1886). Of these, 30 skulls (one in 1885 and the rest in 1886) were taken to Pantusov's headquarters in Vernyi (Almaty). The Burana excavations yielded 49 graves with 50 skeletons (primarily children and the young people) (16 in 1885 and 34 in 1886). Of these, seven skulls were taken by Poyarkov in 1885 and a further seven by Fetisov in 1886. No graves were excavated in the course of the 1892 diggings in either cemetery. In April 1888, 33 skulls (27 from Kara-Djigach and six from Burana) were sent by Pantusov to the Imperial Archaeological Commission in St Petersburg, which, in turn, transferred these to the Kunstkamera museum of the same city (also known as the Peter the Great Museum of Anthropology and Ethnography). 16 As of today, only 22 skulls are kept in the Kunstkamera museum, several having been discarded or presumably lost over the course of time. 17 Likewise  Slutskii, Arthur Hjelt, François Nau, and T. W. Thacker. 18 Since then, a further 60 or so stones (some illegible or without inscriptions) have been discovered, mostly by local residents; these have been published, in several series, by Chetin Dzhumagulov, Wassilios Klein, Mark Dickens, and others. 19 As of today, only 200 stones are housed at several museums: about 125 in the St Petersburg Hermitage and the rest in museums in Russia (Moscow, Kazan, Omsk, and Novosibirsk), Kazakhstan (Almaty), Kyrgyzstan (Bishkek and Burana), Turkmenistan (Ashgabat), Tajikistan (Pandjakent) and Uzbekistan (Tashkent), Finland (Helsinki), France (Lyon and Paris), Germany (Munich), and the United Kingdom (Durham and London). The whereabouts of the remaining 430 or so stones are unknown. 20 The vast majority of the 630 tombstones are written in Syriac, a few outliers in Turkic or Syro-Turkic mixture, and one in Armenian. Of these, 467 tombstones (74 per cent of the total) are dated according to the Seleucid calendar used by local East Syriac communities, running between 1 October of the previous year to 30 September of the next year; most of the headstones also are dated, in addition, according to the 12-year animal cycle. 21 The dated stones cover the period between the Seleucid-style years 1559 (1247-1248) 22 and 1656 (1344-1345); 118 of 467 (thus, one-quarter of all dated stones) are dated to 1649-1650 (1337-1338/1338-1339), the years of the plague outbreak. The remaining 166 (26 per cent) are either undated or in a poor condition with illegible dates. Of 630 tombstones, 623 (including 463 dated) indicate the gender of buried people, of which 607 show their proper names; the gender of a further 15 burials (including four dated) can be deduced on the basis of their adjectives preceding damaged names. The epitaphs also indicate, roughly, the age groups of buried individuals, through the designations ṭalyā/ṭlītā (boy/girl, corresponding to under the age of 12; 54 stones in total), ʿlaymā/ʿlaymtā (young man/maiden, corresponding to the age of 12 to 20; 165 stones in total), mhaymnā/mhaymantā (believers, namely adult individuals aged over 20; 403 stones in total), and sabā/sabtā (old man/old woman; eight in total). 23 Because of low life expectancy, however, the overall proportion of individuals designated as sabā/sabtā is negligible. Also, in some instances, older people appear to be designated as 'believers' rather than 'old men/women'. 24 Because of that, individuals designated as sabā/sabtā have been reckoned together with the mhaymnā/ mhaymantā group. In addition, the epitaphs also indicate a clerical profession, noting priests (qašīšā, qašā), chorepiscopi (korappesqōpā), 'students' (eskolāyā), churchwardens (saorā), as well as some other ecclesiastical positions.
Most tombstones are highly formulaic in nature, revolving around the 'year-namedesignation' structure. A typical epitaph would consist of the following formulae: ba-šnath (in the year) X; hādā hay/hānu qabrāh (this is the grave of) Y; ʿlaymā/ʿlaymtā, or mhaymnā/mhaymantā. Sometimes the age-group designation would be followed by a clerical position or, in some instances, by a supplication formula ('Our Lord, absolve his/her sins', 'let him/her be liberated of his/her sins', 'May his/her memory be blessed, amen'). With the exception of the 1338-1339 mortality crisis, the stones do not indicate the cause of individual deaths.
The epigraphic corpus from the two East Syriac cemeteries in Semirech'ye has several important advantages. Firstly, it covers individuals from both sexes and different age groups. Secondly, it allows a robust comparison of sex ratios between (1) plague mortality (here, the outbreak of 1338-1339); (2) other 'crisis' years (which seem to have been caused primarily by short-term exogenous shocks, as established in Supplementary material, Appendix 1); and (3) 'normal' (attritional) mortality years. 25 Finally, the Semirech'ye corpus is the only demographic dataset from the Mongol-era Central Asia-or indeed the Mongol Empire (including Yuan China, with its highly sophisticated bureaucratic system)-that can be subjugated to a robust statistical analysis on a micro (that is, community-specific) level, not only in relation to plague mortality, but also in terms of long-term population trends. True, Semirech'ye tombstones are not the only example of dated epigraphic corpora from 'medieval' Central Asia. To these, we should add similar 23 25 Such a comparing exercise has been already undertaken by Sharon DeWitte and her colleagues in their pioneering work on two late-medieval cemeteries in London, where they compared sex-ratio mortality during the Black Death (East Smithfield cemetery, 1348-1349), the pestis secunda outbreak (St Mary Graces cemetery, 1361), and attritional late-medieval burials from the latter cemetery. See DeWitte and Kowaleski, 'Black Death bodies'. Unfortunately, the St Mary Graces cemetery burials lacked tombstones and, hence, precise chronologies of attritional burials. late thirteenth/fourteenth-century Syro-Turkic (but primarily Turkic) East-Syriac epigraphic corpora of 21 stones from Almaliq (in western Uyghuristan/Xinjiang, on the modern day Kazakh-Chinese border), 28 from Inner Mongolia, and, most recently unearthed, 36 stones (as of June 2022), mostly lacking inscriptions, from Uch-Aral/Usharal (identified with medieval Ilibalyk), on the lake Alakol, about 570 km northeast of Almaty. 26 Also, there are nearly 200 surviving Muslim Arabic inscriptions, primarily from the thirteenth and fourteenth centuries, from different regions in Kyrgyzstan (but mostly from Osh and Uzgen, both in the Fergana Valley, Southwest Kyrgyzstan). 27 Obviously, these epigraphic corpora pale in size compared to the one at Semirech'ye; and none of the so-far excavated Uch-Aral stones is dated. It would not, in fact, be an exaggeration to say that the Semirech'ye corpus affords our only glimpse into a micro-population history of Central Asia in the pre-modern era, before the Russian Imperial Census of 1897. Although Chinese imperial censuses would record the inhabitants of Central Asian regions under imperial control (such as early eighth-century censuses of the populations of oases of Uyghuristan/Xinjiang, or Qing-dynasty censuses of Mongolian populations), they survive in a summary format, yielding regional totals, rather than local particulars. No censuses seem to have been conducted in Qing-controlled Uyghuristan/Xinjiang, and any pre-Republican figures are based on estimates of travellers or local bureaucrats. 28 Despite its unquestionable importance, the Semirech'ye corpus remained confined primarily to the domain of philologists, ecclesiastical historians, and, more recently, archaeologists. 29 For decades, its significance has been appreciated by only a handful of historians of medieval plague and environment, and only very recently has it received a full-scale treatment. Some historians see the Semirech'ye outbreak of 1338-1339 as a prelude associated with the Black Death, the single deadliest plague pandemic in recorded history, which hit West Eurasia and North Africa between 1346 and 1353. 30 By contrast, some other historians see the Semirech'ye outbreak as an isolated episode, unconnected to the later Black Death. 31 These disagreements are related to a much wider context of centuries-old historiographical controversies regarding the geographic origins of the Black Death. Here, some authors suggested that the catastrophe had originated in regions overlapping with today's borders with China (including the Qinghai-Tibet plateau and the Yunnan/Burma border); some historians suggested either 'Central Asia' generally or the Tian-Shan region more specifically; others proposed alternative regions, including North Iraq/East Anatolia, the Pontic-Caspian steppe, the Volga-Caspian region, Armenian Highlands, West Urals, Western Siberia, Mongolian-Manchurian steppe/Gobi Desert, and India. 32 Recently, Monica Green proposed, on the basis of both palaeogenetic and historical data, a more complex hypothesis, whereby she placed the ultimate origins of the Black Death (the 'Big Bang'/multifurcation discussed below) in the early thirteenth-century Tian-Shan region and its proximate origins in the Caucasus-Volga region in the 1330s/ early 1340s. 33 Most recently, however, genome sequencing of three individuals from plague graves at Kara-Djigach has firmly established that the outbreak in question was indeed associated with the beginning of the Black Death in particular and the Second Plague Pandemic in general. The study showed that the 'pestilence' (mawtānā) appearing on ten headstones from 1338-1339 was indeed plague; evolutionarily, the Kara-Djigach genomes are positioned right on a node, which gave birth to the so-called 'Big Bang'/great polytomy. The latter was a multifurcation event, whereby the main plague lineage (Branch 0) split into four new branches: Branch 1 (travelling westwards and becoming responsible for what became known in West Eurasia and North Africa as the 'Black Death' of the later 1340s and early 1350s), Branch 2 and another short branch, soon to be split into Branches 3 and 4. This means that the 1338-1339 outbreak happened around the time of the node, or shortly (no more than a few years) before the multifurcation. 34 Thus, this study put centuries-old debates related the geographic and chronological origins of the Black Death to rest. This is not to say that the Semirech'ye corpus is without limitations. To begin with, the excavated, photographed, and published stones represent only about 20 per cent of all the burials there, as estimated by Pantusov in the course of the 1885-1886 fieldworks. In the course of the twentieth century, the site topography changed a great deal and the discovery and documentation of the remaining stones may not be easily forthcoming. As we have seen, no more than 60 additional stones have been discovered in the second half of twentieth century, while several Soviet archaeologists who have visited the site have commented on various difficulties in identifying the remains of the cemeteries. Thus, 630 tombstones over a period of just under 100 years is a fairly low number. 35 Campbell, The  Furthermore, the undated/undatable inscriptions, although adding further to our knowledge of sex-ratio and age-group distribution, cannot be contextualised chronologically. Therefore, in the current study, these 163 stones have been left out and the analysis is based on the remaining 467 stones. With the undated stones eliminated from the exercise, the remaining sample represents about 15 per cent of all estimated burials (about 3,000 in total). Moreover, this figure of 15 per cent is the absolute maximum since we do not know for sure if some local community members were buried outside these graveyards.
The paucity of epitaphs with a 'children' and 'old people' designation is related to the single biggest shortcoming of the Semirech'ye corpus-its partial representativity. Despite the remarkably large number of retrieved and documented stones, it is unlikely that they capture residents across all age, gender, and socio-economic groups in any given year. There is no evidence that local East Syriac communities operated active charitable burial societies responsible for funeral services, let alone tombstone carvings. As a result, tombstone epitaphs were undoubtedly financed either by deceased individuals leaving funds towards their future burials, or by their surviving relatives. A cursory look at the epitaphic corpus reveals that despite their formulaic nature, inscriptions tended to vary in their length and degree of detail and fineness of script and decoration. Thus, some inscriptions contained two lines of text carved in a simple script and depicting a plain cross. Some epitaphs had much longer texts executed in fine scripts around embellished crosses and sometimes additional ornamentations. 36 The degree of length and decoration of inscriptions undoubtedly reflects the socio-economic status of interred individual and/or their relatives. In other words, the longer and finer the inscriptions were, the more expensive they were, reflecting an economically better-off status of the individuals buried under them. Some wealthier individuals could commission fine epitaphs; less wealthy ones could command very simple inscriptions; but poor residents may not have been able to afford any at all. Indeed, of the 36 stones unearthed in Uch-Aral/ Usharal (identified with medieval Ilibalyk), as of June 2022, only six have inscriptions. 37 As we shall see later, one conspicuous feature of the Semirech'ye corpus is a disproportionate ratio between male and female epitaphs, and between young men and young women in particular, with the former occupying a suspiciously high share of headstones compared to the latter.
In other words, only a certain proportion of all burials had epitaphs. While it is possible that Pantusov's estimate of 3,000 graves and the recovery of only some 600 stones from Kara-Djigach (that is, 20 per cent of all estimated burials) may actually reflect the approximate ratio between the total burials and headstones, the true proportion was, most likely, higher than that. As Pantusov himself stated in his report, some stones were undoubtedly broken by plough-works done by local Kyrgyz farmers. 38  seasons, Pantusov and his colleagues collected only whole stones, thus leaving behind the fractured ones. For comparison, the 2017 and 2019 excavations at Uch-Aral/Usharal yielded, collectively, 81 graves and 19 headstones (both whole and fractured)-a somewhat higher ratio than that between the estimated total number of graves and the total number of collected stones at Kara-Djigach. 39 In other words, a crude estimate that only one in four of five graves was endowed with tombstones may not actually be too far removed from the truth. The partial representativity of the Semirech'ye corpus is reflected in the paucity of epitaphs with ṭalyā/ṭlītā (boy/girl) and sabā/sabtā (old man/old woman) designations. Most child graves are undated; in fact, 24 per cent of all undated graves have the ṭalyā/ṭlītā designation. Conversely, the proportion of the 'children' group in dated burials appears suspiciously low compared to the ʿlaymā/ʿlaymtā (young men/maidens) group (13 VS 116 in number). The suspiciously low proportion of 'children' in dated burials may reflect a deliberate practice to inter children into graves with simple and undated epitaphs. 40 In addition, this under-representation of child graves could, in part, be attributed to the practice of double and triple burials, whereby several family members would be interred together, as some local graves indeed indicate. 41 Finally, it could also be down to the possibility that, at least in some instances, children may have been designated as ʿlaymā/ ʿlaymtā, rather than ṭalyā/ṭlītā. Because of all these challenges, I have opted to join together the ʿlaymā/ʿlaymtā and ṭalyā/ṭlītā, designating these as 'sub-adults'. The assumption here is that most individuals within the 'sub-adult' group are teenagers and young people, rather than children, who, as noted, seem to have been under-represented in dated epitaphs (while undated epitaphs have been excluded from the dataset; see Table 3).
Likewise, the abysmally low number of individuals designated as sabā/sabtā (old man/ old woman), nine in total, may be another example of under-recording and, thus, misleading. It is possible that some proportion of 'older' people were, in fact, 'mixed' in with the mhaymnā/mhaymantā group. On the other hand, we have to bear in mind the low life expectancy in the pre-Industrial world. Indeed, as Pantusov and his assistant Fetisov reported, out of the total of 116 graves, only three graves contained skeletons of old people, judging by the state of their jaws and teeth (Graves 41 and 77 of the Kara-Djigach cemetery and Grave V of the Burana cemetery). 42 To avoid any false guesswork, I have joined the two groups together into a single 'adults' group.
All these caveats, however, can by no means detract from the remarkable significance of this epigraphic corpus. Its potential is enhanced further when its contents and analysis are supplemented by the excavation diaries of Pantusov and Fetisov, describing, in a meticulous format, the contents of each excavated grave, including skeletal heights and grave goods. Fortunately, during the August 1886 excavations of the Kara-Djigach cemetery, Pantusov marked each stone with a number corresponding to the grave number to which it belonged. Likewise, skulls were assigned the same number as their associated graves and headstones. 43 When Chwolson edited the 1890 edition of tombstones collected 39 http://www.exploration-eurasia.com/inhalt_english/frameset_projekt_aC.html (accessed 19 July 2022). 40 Indeed, out of 33 excavated graves at the Burana cemetery, ten graves were of children (Graves I, VI, VIII, IX, XV, XVII, XXIII, XXVI, XXVII and XXIX), and a further seven graves (Graves XIV, XVIII, XXI, XXIV, XXVIII, XXX, XXXI and XXXII) were of teenagers. AIIMKRAN, F. in August 1886, he took care to assign two numbers to each edited inscription, with the second (bracketed) number standing for the numbers marked by Pantusov, namely corresponding to grave numbers. 44 The parallel between grave numbers, tombstones, and the identity of buried individuals can, thus, be easily established in the case of 58 out of 83 graves from the Kara-Djigach cemetery. 45 In the case of the remaining 25 excavated burials, these either lacked stones or their epitaphs were illegible. Unfortunately, establishing the same parallel for the Burana burials is not possible, because of the fact that local gravestones had been collected in the course of the October 1885 diggings, a year before 33 graves were excavated.
Semirech'ye East Syriac Christians during the Mongol (Chaghadaid) period: an ethnic and socio-economic profile In 1218, the region that was then part of the Qara Khitai Empire came under Mongol control. The consolidation of Mongol rule was accompanied by a piecemeal conversion of the region's arable and urban landscape into pasture for conquerors' livestock. 46 Following the 1259 split of the Mongol Empire into four khanates, Semirech'ye became part of the Chaghadaid ulus. Despite some environmental and demographic destruction, Chaghadaid rulers-at least until their Islamisation in the late 1320s-just as their Qara-Khitai predecessors, showed a considerable religious tolerance towards local Christian, Muslim, Buddhist or Shamanist populations. 47 Of these, East Syriac Christians -regarded by the 'mainstream' Orthodox and Catholic churches as heretics primarily on account of their alleged rejection of Christ's divinity (in reality, the Church of the East maintains that Christ possesses two distinct persons, human and divine)-were not an exception.
East Syriac communities existed in Semirech'ye from at least the eighth century, as both textual and archaeological evidence indicate. 48 Despite their long history, however, very little is known about their lifestyle in both the pre-Mongol and Mongol periods. The surviving epigraphic evidence, together with archaeological reports of the 1885-1886 excavations and some occasional textual references, do shed some important light on various ethno-linguistic, socio-economic, and demographic aspects of Semirech'ye East Syriac Christians in the thirteenth and fourteenth centuries.
The East Syriac settlements, presumably situated in close proximity to the Kara-Djigach and Burana cemeteries, cannot be defined either as 'towns' or 'villages' in the 'Eurasian' sense. Those were gorodishcha, fortified settlements, whose inhabitants were living a sedentary lifestyle, in contrast with their nomadic neighbours, mostly Shamanists or recent converts to Islam. 49 Although, as argued below, the pre-plague population of the 44 In the vast majority of cases, Chwolson was accurate in copying Pantusov's numbers. The only exceptions were 53,4 (22), which should have been 53,4 (2) (Kara Djigach Cemetery, Grave 2) and 48,3 (77), which should have been 48,3 (71) (Kara Djigach Cemetery, Grave 71). This discrepancy seems to have derived from the fact that in both cases, Chwolson edited the inscriptions from photographs of the stones, rather than the originals. Also, 50,18 (27)  Kara-Djigach settlement seems to have reached about 1,250 people (perhaps about 250 households), 50 it does not exhibit 'urban' features similar to some large and vibrant international trade hubs in the Semirech'ye, including Almaliq (in western Uyghuristan/ Xinjiang, on the modern-day Kazakh-Chinese border), Taraz (Jambyl region, South Kazakhstan), Jand (presumably today's Zhan-Kala), and Otrar (in southwestern Kazakhstan). The same forts were 'sedentary islands' in the sea of pastoral nomadism engulfing the vast steppe of the Chaghadaid khanate.
The available epigraphic and archaeological data provide some clues about the complex ethno-cultural background of Semirech'ye East Syriac Christians. Over the entire period, about 65 per cent of all personal names were Turkic and the rest 'Syriac' (Syriacised versions of ancient Hebrew and Greek names). This ratio was by no means constant; over the period circa 1248-1310, it was nearly equal, while circa 1311-1345, Turkic names amounted to almost three-quarters of all personal names. 51 This may indicate a gradual process of cultural Turkicisation. This is reflected not only in a dozen epitaphs in Turkic, but also in the fact that some Syriac epitaph phrases are, in fact, Turkic calques, indicating that local Christians were Turkic speakers. William de Rubruck, the Flemish missionary and diplomat to the Great Qa'an's court in Karakorum (1253-1255), noted that 'Nestorians' did not know Syriac, even though they conducted their liturgy in that language. 52 Although it may indicate that an ethno-linguistic Turkic element was prominent, it was certainly not the only one. As craniological analysis of 23 excavated individuals from the Kara-Djigach and Burana cemeteries, undertaken by Georgii Debets, has revealed, they exhibit Pamirid (Pamir-Fergana) features, characteristic of lowland Tajiks, belonging to the Iranic ethnic group. 53 Indeed, the most recent human aDNA analysis of five individuals (three from Kara-Djigach and two from Burana) revealed a close affinity to Tajik, rather than the Turkic populations of Central Asia. 54 This thin sample, however, should not be taken as indicative of the situation as a whole. In reality, epigraphic evidence suggests an ethnically diverse profile of the two communities. Furthermore, the epitaphs mentioned at least one Mongol (Mogolayā), one Uyghur (Uigur), and one Armenian (Armnayā). 55 Several individuals are designated as Almāligayā/Almāligaytā, namely 'of Almaliq', and one as Kaškarayā, that is 'of Kashgar'. 56 Almaliq and Kashgar (both in Western Uyghuristan/Xinjiang) were important international trade hubs and ethnically and religiously diverse cities, boasting sizeable East Syriac communities. Finally, two individuals were designated as 'Chinese'. 57 In other words, the ethnically diverse profile of 50 The approximate formula of one household=5 people as a norm is invoked on the basis of eight-century Chinese censuses and Russian reports of Kyrgyz population in the mid-nineteenth century. East Syriac communities of Kara-Djigach and Burana was closely related to immigration from other parts of Semirech'ye and further regions of Central Asia. In this respect, these communities represent a microcosm of late-medieval Semirech'ye human landscape in general, characterised by the presence and mixture of Indo-European, Turkic, and Mongolic ethnic and linguistic groups. 58 This supports one recent human aDNA study of historical populations of Central Asian steppe, which revealed that up until circa 1600, these were characterised by high genetic heterogeneity-in contrast to more recent populations, marked by increased homogenisation, owing to strict endogamy. 59 It was indeed thanks to immigration that the East Syriac community grew considerably in size between circa 1250 and 1300.
Although the East Syriac communities were religiously exclusive, both epigraphic and archaeological evidence indicates that some members converted to Islam. One epitaph from 1332-1333 stated that three people buried in that grave 'died in Islam' (tlathā po aoșāgo Musurmān). The 1886 excavation of the same grave revealed three sitting burials -in contrast with lying burials of other individuals. 60 The bodies showed no signs of violence, indicating a peaceful conversion. The fact that one of these graves contained multiple valuables hints that even after death the individuals continued to be fully respected members of their community. It should be pointed out that the three converts died during the brief reign of Tarmashirin Qan (1331-1334), who himself had converted from Buddhism to Islam in 1328-1329. Although Tarmashirin encouraged conversion among his subjects, there is no evidence that he ever attempted to force it. 61 It is within this context that the three East Syriac Christians' conversion to Islam is to be viewed. Despite the latter's acceptance by their former co-religionists, these conversion cases were clear outliers: with a possible exception of one additional (undatable) tombstone, there is no evidence of any further instance of conversion to Islam. 62 We know very little about the occupation profile of Semirech'ye East Syriac Christians. About 30 per cent of buried males (106/365), in both dated and undated epitaphs, were designated as clerks, occupying different ecclesiastical positions. Of these, 55 were designated as 'priests' (qašīšā, qašā), 32 as 'students' (eskolāyā), and a further 19 occupied various other clerical roles, including churchwardens, chorepiscopi, and teachers. The disproportionate share of East Syriac men being ordained as priests has been noted by several thirteenth-century Western authors, including Rubruck, who visited the region in 1253, and stated that this practice was related to the fact that bishops had barely visited these parts once in 50 years. 63 Interestingly, many eskolāyā were, in fact, boys, as their skeletal evidence shows. 64 Again, this resonates with Rubruck's statement that even male children still in the cradle were ordained as priests. 65 A high proportion of ordained priests does not mean that the same East Syriac men designated as qašīšā/qašā or eskolāyā were, in fact, involved in church roles.
Some locals were undoubtedly involved in international trade along the long-distance trans-Asian trade routes (often erroneously called the 'Silk Road'). In particular, the Kara-Djigach and Burana forts, alongside other East Syriac settlements in Semirech'ye, including Krasnaya Rechka, Ucharal (Ush-Aral, identified with Ilibalyk), and Novopokrovka, were situated at the heart of this trade network-halfway between the two linked trade emporia of Otrar and Almaliq-and, as such, they may have served as intermediate stops of rest and trade for passing merchants. 66 Rubruck referred to East Syriac Christians as 'usurers', presumably implying their financing activities. Marco Polo, in his Travels, too, referred to them as 'capital merchants'. 67 The 1885-1886 excavations unearthed some grave goods that reveal Semirech'ye Christians' involvement in long-distance trade. These include pearls (originating in the Persian Gulf, Indian and Pacific oceans), and corals and Marginella shells (presumably from the Mediterranean Sea). 68 In addition, some graves contained precious metals, stone beads, golden brocade cloths, and fine silk textiles. 69 It is unclear if silk clothes were acquired from elsewhere or produced locally: as Marco Polo pointed out, some East Syriac Öngüts of Inner Mongolia were also skilled textile artisans. 70 Those buried goods closely resemble artefacts most recently unearthed in another late thirteenth/ early fourteenth-century East Syriac cemetery at Ilibalyk (Ush-Aral). 71 Numismatic evidence from Kara-Djigach sheds some additional light on the financial and commercial activities of the local community. This consists of two Chaghadaid-era hoards found near the Kara-Djigach cemetery, published, respectively, in 2002 and 2016, and containing 139 (129 dinars and 10 dirhams) and 26 coins each (20 dirhams and six dinars). Taken together, the hoards included 55 coins from the mint of Bukhara, 47 from Termez (South Uzbekistan, on the Uzbek-Afghan border), 31 from Samarqand, 16 from Otrar, three from Badakhshan (North-East Afghanistan), two each from Shash (Tashkent) and Almaliq, and one each from Taraz (formerly Dzhambul, South Kazakhstan, on the Kazakh-Kyrgyz border) and Soltaniyeh (the Ilkhanid capital in North Iran). 72 The minting provenance of these coins indicates that long-distance trade stretched to Khwarazm, Transoxiana, and as far as Balkh, Badakhshan, and North Iran (with Soltaniyeh situated some 3,000 km southwest of Kara-Djigach). The circulation of coinage from these mints in the Semirech'ye region is reflected also in other hoards from the Chu and Talas valleys. 73 Most recently, it has been argued that Kara-Djigach may have had its own mint, striking low-quality imitation coins, whose circulation was limited to the Chu Valley. 74 Although financial and commercial activities might well have involved many Semirech'ye East Syriac Christians, it is possible that at least some of them were engaged in farming. In describing the East Syriac Öngüts of Inner Mongolia, Marco Polo noted that they practised both arable and livestock economies. 75 The cultivation of millet is indeed noted by both Giovanni da Pian del Carpine (1246) and Rubruck. 76 Semirech'ye East Syriac Christians during the Mongol (Chaghadaid) period: demographic growth and decline The continuous nature of the Semirech'ye tombstone chronology from the Kara-Djigach graveyard allows us to follow the main demographic of the local community-in particular, its long-term growth and annual mortality levels. If the earliest tombstone from Kara-Djigach is dated to 1248, this may imply that the community may have been founded there in the early thirteenth century, following the Mongol conquest in 1218, but most likely in the aftermath of the widespread environmental and demographic destruction inflicted by their forces in the 1220s and 1230s. If we are to assume that the community was founded closer to the date of the earliest tombstone (1248), then we may postulate that a non-negligible proportion of individuals buried in the course of the first three or four decades following the settlement foundation were immigrants. 77 As we have seen, some of these immigrants undoubtedly came from Almaliq, as it is indicated in two epitaphs from the 1280s bearing the toponomyc designation Almāligayā/ Almāligaytā. 78 Moreover, five out of the total of nine individuals designated as 'old people' (sabā/sabtā) in the Semirech'ye corpus died between 1252 and 1286. This fact implies that these five individuals were born before the foundation of the Kara-Djigach settlement and came there as immigrants. Although very few epitaphs hint at the geographic origins of migrants (of the total 630 inscriptions, both dated and undated, only seven mention a specific location, in all cases Almaliq and Kashgar), we may speculate that most of these came from other East Syriac settlements in Semirech'ye and the Tarim basin. Apart from Almaliq (and indeed Kashgar), this region was a home to numerous vibrant East Christian communities, situated in or next to Burana, Krasnaya Rechka, Ush-Aral (identified with Ilibalyk), Novopokrovka, Kok-Djar, Saruu, Tash-Rabat, Ivanovka, and Zhuuku (on the southern shore of Lake Issyk-Kul'). 79 It is unclear whether these immigrants were drawn by 'push' or 'pull' factors. On the one hand, numerous contemporary authors and travellers report the destruction and decay of Semirech'ye towns in the aftermath of the Mongol Conquest in 1218. Hence, it is possible that these individuals were, in fact, refugees. On the other hands, some cities-Almaliq first and foremost-were spared by the Mongols and continued prospering, in the course of the thirteenth century. 80 Hence, some Almaliq (and Kashgar) residents may have been attracted by commercial opportunities arising along the long-distance trans-Asian trade routes and migrated to Kara-Djigach, which was conveniently situated at the heart of the northern branch of these routes.
There can be little doubt that immigration played a paramount role in the demographic growth of the Kara-Djigach community during the first decades of its history. Initially, growth was slow. As Figure 1 and Table 1 indicate, before the 1280s, there is one surviving tombstone per year, reflecting the small size of the community-even if we assume that these cover only 15 per cent of the total population. The crisis of 1264, discussed below (and in a further detail in the Supplementary material, Appendix 1), undoubtedly contributed to the temporary slowdown of demographic growth. The recovery, however, came shortly afterwards: as we can see, the decadal average of annual surviving tombstones rose considerably in the course of the following decades-from one in the 1270s to five in the 1300s.
Population growth continued in the following decades, right until the sudden and devastating outbreak of plague in the summer of 1338. The fivefold increase over just 30 years implied an annual population growth of 5.5 per cent, a remarkably high figure compared to Western Europe in the same period. 81 Such a fast growth would have been impossible without high fertility and intense immigration. As we have seen above, there is sufficient evidence about immigration into Semirech'ye communities.
As Table 2 indicates, in pre-plague years, the proportion of sub-adult (children and young people) epitaphs accounted for about three-quarters of all headstones. Although the fact that some children were interred with their parents and lacked their own epitaphs conceals the true proportion of child burials, there is no doubt that the preponderance of adult gravestones reflects the fact that most people died as adults and that sub-adult mortality was less common, as far as non-plague years are concerned. Child survival and adolescence were a crucial factor in ensuring high fertility rates, which were, as we shall see later, connected to the very low age of women's first marriage, standing between circa 12 and 15.
In particular, high fertility and immigration would be essential in sustaining demographic growth in the face of intermittent mortality crises. Mortality crises are understood here as high spikes in numbers of tombstone counts (serving as proxy for annual burial levels), compared with 'average' tombstone counts in adjacent years ( Figure 2). The single most pronounced spike can be seen under the years 1338 and 1339 and is related to the plague outbreak in the summer of 1338 (118 tombstones out of the total 467 dated stones are dated to these two years). Although this remarkable spike undoubtedly reflects a harsh mortality crisis, only ten out of 118 tombstones, for 11 individuals, record 'pestilence/plague' (mawtānā). These inscriptions contained the formula 'X died of pestilence' (mīt[ā] [bi-]mawtānā). 82 Obviously, this can by no means mean that only these 11 individuals perished in plague, while the remaining 108 or so individuals were miraculously spared the pathogen and died of something else. Plague is a highly contagious disease with remarkably high and fast transmission rates. Given the closed and, as we shall see below, dense nature of local settlements in the Semirech'ye region, it is to be expected that a plague outbreak would result in high mortality-as was indeed the case here. If anything, this paucity of epitaphic references to plague has to do with the fact that not every deceased individual could afford the luxury of having these carved on their graves. As we have seen above, in the absence of a perpetual and active charitable burial society,  tombstones were undoubtedly financed either by deceased individuals leaving funds towards their future burials or by their surviving relatives. Again, we can assume that the longer the inscriptions, the more expensive they were. Hence, their length may be correlated with the wealth of buried individuals, and/or their relatives. Although it is undoubtedly the single most devastating disaster, we also have to account for more minor mortality crises, as reflected in 'lower' spikes in the numbers of annual tombstones- in 1264, 1286, 1288-1289, 1292, 1301, 1307, 1316, 1320, 1323-1324, 1327, 1329, 1331, 1336-1337, and 1341-1342 (Figure 2). As discussed in the Supplementary material, Appendix 1, most of these excess mortality spikes may have been caused by subsistence crises triggered by a combination of exogenous and endogenous factors. While these non-plague mortality crises undoubtedly hindered the intense population growth of Semirech'ye East Syriac communities, the plague outbreak, as we shall see, led to them vanishing almost immediately.
One way to estimate the total population of the East Syriac community on the eve of the plague outbreak is to add together the annual numbers of surviving tombstones between 1335 and 1345 (the last dated tombstone), assuming that most, if not all, of the survivors of the plague (who died between 1340 and 1345) resided there on the eve of the plague outbreak. This renders a total of 191 tombstones, which, if deflated by 0.15 (as deployed in Table 1, to account for missing burials), hints that the population size circa 1335 may have been around 1,270 people. Deflating the hypothetical figure of 35 annual burials (five annual tombstones deflated by 0.15 to account for missing burials) by 1,270 yields the annual death rates of 2.8 per cent (or 28 per 1,000)-largely comparable with 2.5-3.0 per cent in Western Europe around the same time. 83 No immigration, however, could save the Semirech'ye communities from a devastating plague outbreak, which arrived in, most likely, the summer of 1338 and ravaged the population into the next year. 84 A crude estimate suggests that the outbreak may have killed about 75 per cent of the local population. This estimate derives from the fact that there are 118 tombstones for the plague years and 41 tombstones related to the plague survivors, all of whom died between 1340 and 1345, at which point the Semirech'ye communities ceased to exist. In other words, of 159 individuals, 118 died in the plague. This is, obviously, just a fraction of the total number of burials; as indicated below, only a certain percentage of graves-perhaps 20-25 per cent-were endowed with headstones. Therefore, it is unclear how reliable this sample of 159 excavated stones is, when estimating the mortality rates during the plague outbreak. In any event, if this estimate is not too far from reality, then it appears that the plague was more devastating in Semirech'ye than it was in Western Europe and the Middle East a decade later, where mortality rates stood, in various regions, in the region of 50-60 per cent. 85 Explaining such exceptionally high mortality rates, even in comparison to the Black Death in Europe and the Middle East, is hardly possible at this stage. Although it may have something to do with the population densities of Semirech'ye sedentary fortified settlements (gorodishcha), which were undoubtedly much thicker than those of nomadic pastoralist communities, they were undoubtedly not nearly as thick as European and Middle Eastern cities. As some Soviet archaeological surveys reported, an average gorodishche in Chui Valley had fortified walls measuring about 500 x 500 metres (=25 hectares). 86 If the East Syriac settlement related to the Kara-Djigach cemetery was about the same size, and if its pre-plague population peaked at about 1,250 people (see above), then its population density may have stood at about 50 people per hectare, in contrast with the average of 200-250 people in West European cities circa 1300. 87 Another possibility-now that it has been established that the 1338-1339 outbreak was indeed associated with the 'Black Death' in Europe, North Africa, and the Middle East-is that the plague was particularly virulent at the beginning of its westward journey from Central Asia. Recent palaeogenetic research has established the phenomenon of virulence-related genes attenuation (reduction and loss) in historical Yersinia pestis bacteria. 88 Such processes, however, happen over centuries or at least several decades, rather than a few years. As one recent study of the so-called First Plague Pandemic (also known as the early-medieval or Justinianic plague) has found, it took at least 80 years for the plague lineage (0.ANT4) to lose some of its virulence genes, after the plague appeared in Egypt in 541. 89 When the plague was ravaging West Eurasia and North Africa between 1346 and 1353, it was certainly highly virulent, claiming at least 50 per cent of local populations-and often figures were higher than that. Thus, it is extremely unlikely that some ten years would be sufficient for the plague strain to lose some of its virulence genes. In the absence of palaeogenetic data on virulence, however, this hypothesis cannot move beyond a speculative framework.
Who were the survivors of the plague? Were these a few lucky locals or new immigrants moving in after the crisis? Obviously, the scant and laconic nature of epitaphs cannot provide an adequate answer. However, there are at least two headstones hinting that at least some survivors were locals, rather than immigrants. One of these individuals was one 'Īlyā the priest, son of Yoḥannān (John) the priest' who died in 1339-1340 (1651). Ilya seems to have been a brother of Aoloṭako, son of Yoḥannān the priest, who had died in 1316-1317 (1628). 90 Another individual, Bačaq-Tärim, a young woman who was the daughter of Ṣadikim the priest, who died in 1340-1341 (1652), may have been the daughter of Ṣadikim the churchwarden, who perished in the plague. 91 Another woman, called Qyamta, was designated as Kaškarayā (presumably, for Kaškaraytā), namely 'of Kashgar'. 92 Hence, it is possible that there were some attempts to solve the demographic vacuum by encouraging immigration. However, the fact that no other individuals buried between 1340 and 1345 are designated as such by an immigrant surname (such as Almāligayā/ Almāligaytā), together with the scant nature of the available material related to the plague survivors, does not allow for any further assumptions.
It is unlikely, therefore, that the epigraphic evidence reflects the real sex ratio. Despite the fact that there were undoubtedly more men than women in Chaghadaid Semirech'ye, the figure of 1.39 in non-plague years nevertheless comes across as suspiciously high-in particular, given the fact that some better-off East Syriac men practiced polygamy, as mentioned by some Western contemporaries. 95 If that were the case, then we end up not only with a disproportionate surplus of men, but also with a disproportionate surplus of single men. Such a demographic composition would have precluded any prospect of fast population growth, even if we were to account for constant immigration. Hence, the available epigraphic evidence is likely to be biased and, thus, does not reflect the true ratio between the genders, which appears unlikely to have been higher than, say, 1.20.
The same problem of skewed sex ratios is reflected in archaeological finds from later medieval English cemeteries, where, in some instances, the figures were unrealistically high, standing at 1.50 and higher, even though late fourteenth-century tax records indicate a ratio of about 1.16. 96 As Maryanne Kowaleski has contended, those skewed sexratios, as indicated in burials (but also in censuses), should not be taken as the indication of a real shortage of women, but rather as a reflection of 'missing women', whose poverty may have prevented them from being given a proper burial in parish churchyards (or prompted them to evade paying taxes). 97 It is unclear why the sex ratio was so skewed here and what happened to all the 'missing women'. As Figures 3 and 4 indicate, there were neither gender-nor age-specific designated sections in the Kara-Djigach cemetery, implying that women were not excluded from cemetery burial. Moreover, even those considered 'sinful' were extremely unlikely to have been denied a cemetery burial: as we have seen, local converts to Islam were buried alongside their Christian relatives and neighbours-something that would not be likely in the Orthodox or Catholic contexts.
A further hint, however, may be provided by a comparison of sex ratios across different age groups. As Table 4 shows, the ratios were unrealistically high within the sub-adult group-standing at 1.85, if accounting for all non-plague years, or 2.13, if considering only the pre-plague period. By contrast, the respective figures within the adult group stood at 1.34 and 1.27, which were undoubtedly closer to real sex ratios. In other words, there is a problem of, specifically, 'missing' young women. One possibility is that the graves of some younger women, in contrast with their adult counterparts, would not be endowed with tombstone epitaphs-possibly because of their worse-off socio-economic status. If that was the case, then a non-negligible proportion of younger women remain 'undocumented' or 'missing'-just as they were in late-medieval England. 98 In other words, the collected and published epitaphs may not reflect the true sex ratio of people buried at the Semirech'ye cemeteries. In the absence of any additional data, however, this hypothesis cannot be taken any further.

Sex-and age-selectivity in mortality crises
One main finding deriving from the analysis of the Semirech'ye corpus, shown in Table 2, is that there was a significant decline in the sex ratio during the 1338-1339 plague epidemic. In other words, a far larger proportion women were dying in the course of the plague outbreak than in other years, be it 'normal' or 'excess' mortality (that is, other mortality crises years).
The sex ratio fell drastically from 1.39 in non-plague years (or 1.36 in pre-plague years) to just 1.00 during the plague outbreak; namely, there was a gap of about 0.39 (or 0.36) between non-plague and plague years. This difference conforms to the findings by Curtis and Roosen for late-medieval Belgium, which showed a similar fall from 1.18 in non-plague years to 0.94 during plague outbreaks in Hainault between 1349 and 1450 (namely, the gap of 0.24 between the sex ratios in non-plague and plague years). 99 Although the decline in sex-ratio mortality is clearly detectable across the entire sample of dated burials, it appears especially pronounced within the sub-adult group, falling from 2.13 if accounting for all the pre-plague years, or 1.73 if accounting for non-crisis years only, to the remarkably low figure of 1.00 (Table 4). This is in contrast with a less notable fall from the respective values of 1.27 (if accounting for 'normal mortality' years only), or 1.25 (if accounting for non-plague years only), to 1.00 in the case of adults. In other words, although women were more susceptible to plague than men across all age groups, they were especially susceptible within the sub-adult cohort.
A close analysis of sex-selectivity mortality patterns within sub-adult and adult cohorts in non-plague crisis years reveals changes, too. As Table 4 indicates, there was an increase in sex ratio within the sub-adult cohort in non-plague crisis mortality years, with the figures rising from 1.73 to 1.94. Similarly, the figures rose from 1.25 to 1.44 within the adult group. In other words, during these short-term episodes of excess mortality, most of which seem to have been connected to subsistence crises, both young and adult men were particularly susceptible. As we shall see below, this, again, conforms to age-specific patterns in famine mortality, as numerous historical examples demonstrate.
Explaining the pronounced fall in sex ratios during the 1338-1339 plague outbreak is by no means straightforward, as it is unclear whether it was linked to socio-cultural (endogenous) or biological (exogenous) factors. When accounting for socio-cultural factors, it is important to consider gender-specific roles. As some studies of late-medieval England and the Low Countries have shown, women's domestic functions, related to household caregiving tasks, requiring that they spent disproportionate amounts of time in houses, may have exposed them more than men, whose gender-specific roles required them to conduct their work outdoors, or at least outside their houses. 100 As we have seen above, we know very little about the occupations and gender roles of the Christian communities of Semirech'ye, apart from their involvement in ecclesiastical roles, international trade, financing, and crafts. These, however, can hardly be correlated with plague spread mechanisms. As we have seen, some East Syriac households may have been involved in agriculture. Crop cultivation and livestock herding were predominantly male activities, implying that local men would spend more time outdoors than their mothers, wives, sisters, and daughters. In the Semirech'ye context, this would imply an elevated, rather than lowered, risk of men's exposure to plague, given their proximity to infected rodents, primarily marmots, but also a range of 'secondary' plague hostsmice, voles, susliks, hamsters, stoats, polecats, hares, foxes, and badgers. 101 Yet this was not the case here, given the disproportionately high mortality of women. Conversely, we can assume that local women's tasks were related primarily to household caregiving, similarly to their counterparts in Western Europe. The disproportionate concentration of women in a close work environment within their houses could be intensified further by the fact that some better-off East Syriac men practised polygamy. 102 This could potentially encourage the human-to-human spread of plague, either via ectoparasites (bubonic) or directly (pneumonic). In other words, the fact that both men and women were, at least in theory, equally exposed to plague (men via direct contacts with rodent plague hosts and women via contacts with other household members) is at odds with disproportionate plague mortality among women.
If socio-cultural factors do not sufficiently explain the impact of plague outbreak on falling sex ratios, we may turn to an alternative 'biological' or 'intrinsic' mechanism explanation. This idea can be tested, once we disaggregate the gendered burials into their respective age groups and take into account the biological mechanism explanation. As we have seen, it was young women who were particularly susceptible to plague. One possible explanation for the higher risk of plague exposure in younger women is pregnancy. The age of first marriage in late-medieval East Syriac communities was lower than in Catholic Europe: according to the Nomocanon of Abdisho bar Berika of Nisibis (d. 1318), it was normally 14, but no lower than 12, for girls. 103 Similarly, the Nomocanon of Bar Hebraeus (1226-1286) decreed that the age of majority was 12 for girls and 14 for boys. 104 The early age of marriage in East Syriac communities in early nineteenth-century Persia was reported by Justin Perkins (1805-1869), an American Presbyterian missionary and Orientalist, who stated that it stood at between 13 and 15 for girls and between 15 and 17 for boys. 105 Coupled with the fast demographic growth of the Semirech'ye communities between circa 1248 and 1345, and high rates of infant mortality, it appears that the ʿlaymtā cohort was particularly fertile, with young women capable of bearing several children before reaching the age of 20. As several studies have shown, contracting plague is highly dangerous for both expectant mothers and their foetuses; without timely antibiotic intervention, the infection of the placenta will result in miscarriage or premature stillbirth and, subsequently, in a perinatal death. 106 Indeed, there is at least one grave where remains of a foetal skeleton were found around the pelvic region of an unidentified woman, presumably indicating the 'coffin birth' phenomenon. 107 It should be noted that only 'mature' foetus skeletons (that is, close to or around a delivery date) tend to be preserved in soil, whereas the bones of 'younger' foetuses, because of their frailty and underdevelopment, are prone to fast post-mortem disintegration. Therefore, most miscarriages and stillbirths caused by maternal plague contraction will not be identifiable as far as archaeological evidence is concerned.
The elevated risk of plague mortality in young women has also been shown for other historical outbreaks. Thus, during the 1630 outbreak in Nonantola, the sex ratio within the 15-19 age group fell from 1.3 in 'normal' years on the eve of the plague to 1.1. 108 Similarly, during the 1452 and 1523 outbreaks in Milan, young women faced an increased risk of death compared to their brothers and husbands. Alfani and Cohn, and Alfani and Bonetti have argued that the elevated risk of plague mortality in young women was related to the beginning of their fertility and pregnancy period after puberty. 109 The average age of menarche in late-medieval and early modern northern Italy was 14, while the average age of first marriage was 16 for young women. This was perhaps a bit higher than among Central Asian East Syriac Christians, but not high enough to make much of a difference, given that not every potential bride aged 13-15 would have been fertile. Likewise, during seventeenth-century plague outbreaks in England, mortality rates were the highest among pregnant women. 110 In other words, early pregnancies of young women may have played a paramount role in the decreased sex ratio.
Biological factors seem to have been as decisive in other crisis years. As we have seen, the sex ratio rose visibly from 1.73 in non-crisis years to 1.94 within the sub-adult cohort, and from 1.25 in non-crisis years to 1.44 within the adult group (Table 4). In other words, young and adult men were disproportionately vulnerable to these short-term mortality crises, most of which seem to have been related to climatic shocks and subsistence crises (Supplementary material, Appendix 1). This trend conforms to the 'female advantage mortality' phenomenon spotted in some historical famines-in most instances, sex ratios rise dramatically within adult cohorts. Thus, the sex ratios in famine-related contexts in the respective age cohorts of 1-19 and 20-59 stood at 1.06 and 1.14 during the Bangladesh. 111 Similarly, during the Tenpō famine in Japan (1833-1837), the respective figures for the age cohorts of 15-29 and 44-59 stood at 0.92 and 1.52. 112 It has been suggested that adult women tend to perish in famines in smaller proportions than adult men because of their biological and physiological mechanisms. Firstly, oestrogen makes adult women better suited to resist famine-related diseases (chiefly typhoid). Secondly, adult women's bodies are smaller and lighter, with a slower metabolism and a larger proportion of natural fat content, compared to those of their male counterparts. 113 Although there is much evidence of 'female advantage famine mortality', it should not always be taken for granted: for instance, during the 1590s crisis in England and the Great Irish Famine of 1845-1852, the differences in mortality ratios between the sexes was barely noticeable. 114 Implications of sub-adult female mortality in Semirech'ye The disproportionately high mortality rates in young women during the plague outbreak and that in young men during excess mortality crises implied that the relative share of sub-adult deaths in all deaths went up in both instances, compared to 'normal' years (Tables 2 and 4). This is largely comparable with other historical plague outbreaks and famines. In the case of plague, this trend can be discerned in the skeletal assemblages from late-medieval London, where the proportion of sub-adults aged 20 and below from non-plague burials, the Black Death, and pestis secunda cemeteries stood at, respectively, 35, 49, and 51 per cent. 115 117 By targeting women, and especially young women, the plague outbreak of 1338-1339 wiped out the single most fertile cohort within the Semirech'ye community, skewed the gender ratio most unfavourably, and thus destroyed any prospect of biological reproduction within the same communities. The survivors of the plague were primarily men, both young and adult. Indeed, as Table 4 indicates, in the aftermath of the plague (1340-1345), were some kinship links between the Semirech'ye and East Syriac Christians of Almaliq and Kashgar, prompting the former to migrate to these cities after 1345. The situation in Almaliq and Kashgar became tense again in the 1370s, in the context of Tamerlane's campaigns, particularly his devastating raids in the Almaliq region in 1375, followed by the ransacking of Kashgar in 1389-1390. 121 The absence of post-1372 stones from Almaliq may indeed reflect the end of the East Syriac community in the city in the context of Tamerlane's fiercely anti-Christian (and indeed anti-Buddhist and anti-Hinduist) policies.

Conclusions
The analysis of the unique corpus of late-medieval epitaphs from Semirech'ye offers a unique glimpse into pre-modern Central Asian demography, on the one hand, and a contribution to our existing knowledge of plague demography, on the other. On a basic level, it reveals the fast growth, then a sudden decline and vanishing of a multicultural community of East Syriac Christians in Chaghadaid Central Asia. As we have seen, it grew very fast between circa 1270s and 1300s; on the eve of the plague, it boasted a population of about 1,250 people. Such a fast growth was possible thanks to a permanent influx of new immigrants from other parts of Central Asia and possibly beyond. The growth of a Central Asian Christian community is at odds with gloomy depictions of Mongol conquests and the destruction of local populations. If anything, the attitude of Mongol authorities towards East Syriac and other Christians varied from tolerance to respect and admiration and, in some isolated cases, conversion. Some campaigns of Chaghadaid rulers may have resulted in the massacre of some local community members and intermittent demographic setbacks, but these had nothing to do with their religion.
The sudden arrival of the plague in summer 1338 resulted in the death of about threequarters of local community members, in the space of just one year. A close analysis of the epigraphic data corroborates the idea that plague was selective with regard to both the sex and the age of its victims. Specifically, it tended to kill disproportionately more women than men, and more sub-adults than adults. When regarding the effects of plague across both genders and age groups, it appears that the plague was particularly virulent in young women: as we have seen, the sex ratio within the sub-adult cohort buried at the Kara-Djigach cemetery fell from 2.13 in the period 1248-1337 to 1.00 during the plague. Obviously, the highly skewed sex ratios are to be approached with caution and not be taken at face value. At the same time, there is no question that the sharp decline, however unrealistic, still reflects the fact that plague tended to be particularly devastating in young women.
These patterns are in agreement with other historical plagues in pre-Industrial Europe. This striking similarity, notwithstanding different chronological, geographic, and cultural contexts, may lend credibility to the idea that 'female disadvantage plague mortality' may have been a product of intrinsically biological, rather than socio-cultural, differential factors. Naturally, in absolutising biology as a singular variable, one inevitably runs the risk of falling into the trap of determinism. Hence, both biology and culture need to be considered; yet, the relative contribution of each variable may not be equal, and it is possible that the former was a more heavy-weighted factor than the latter. Such a cautious approach is in line with the recent view of Curtis and Roosen. As the authors have commented in reference to late-medieval Hainault, 'we still know relatively little about the daily behaviour of men and women in the medieval period'. 122 By contrast, it would not be an exaggeration to say that we know virtually nothing about the daily lives and behaviour of men and women in fourteenth-century Semirech'ye, which was ethnically, religiously and culturally much more diverse than the late-medieval Low Countries.
'Female disadvantage plague mortality' stands diametrically in contrast with 'female advantage famine mortality'. This is reflected in the inverse trends in sex ratio between plague mortality and other excess mortality shocks, most of which are taken to be related to subsistence crises. Again, the heightened mortality ratio corroborates our knowledge about famine mortality, whereby adult men tend to die disproportionately more than their wives and sisters. Again, biological differentials seem to play a paramount role in this phenomenon, as some studies have indicated.
Although the analysis of the Semirech'ye data may answer some questions, it also poses some additional ones. If we stick to the biological interpretation of 'female disadvantage mortality' during plague, then what factors, apart from pregnancy, account for this disadvantage? Given that not all younger women were fertile around the plague time, pregnancy alone can hardly explain it. Did other mechanisms, such as oestrogen, post-partum frailty, and lactation play a role? Or was it about some biological peculiarities in men that gave the latter some immunological advantage over their female counterparts? These links between gender-specific biological differentials and plague mortality, convincing yet hypothetical, are begging to be studied by multidisciplinary teams of historians, palaeopathologists, immunologists, and molecular biologists.
Another point to consider is pre-existing health conditions of both men and women. As recent work by Sharon DeWitte and her colleagues has shown, frailer individuals exhibiting physical stress markers were more likely to die during the Black Death, as the evidence from East Smithfield, London, demonstrates. 123 Indeed, England and other parts of northwestern Europe had experienced the Great Famine of 1315-1317, the Great Bovine Pestilence of 1319-1321 and subsequent dairy intake deficiency, as well as declining living standards, all setting the stage for the devastating impact of the plague. But if our exogenous interpretation of non-plague mortality crises in Semirech'ye in Supplementary material, Appendix 1 is correct and the local communities experienced harsh winters, excessively damp or dry summers, crop destruction, livestock mortality, and ensuing starvation in the pre-1338 era, then much the same stage for the plague has been set there. As we have seen, during those short-term episodes of subsistence crises, adult men died disproportionately more than both adult women and young people. Could it be that the female survivors of those short-term crises had immune systems that had been compromised to the point that they could not resist the plague bacteria? As for the previous issue, the question of the impact of pre-existing stress on pandemics, although studied by several scientists, still awaits a thorough historical, immunological, and microbiological investigation. 124 It is yet another example of where humanists, archaeologists, and scientists should join hands and work together, in order to answer this and other pressing questions in plague studies.
The issue of pre-existing health conditions, in the context of late-medieval plague outbreaks, is closely related to the so-called 'Fourteenth Century Crisis'. For decades, historians have talked about this phenomenon, focusing primarily on Western and Central Europe, without considering other parts of the world. In Europe, the essence of the crisis consisted of various manifestations-exogenous, demographic, and endogenous. 125 The exogenous aspects included the transitional period from the Medieval Warm Anomaly (MWA) to the Little Ice Age (LIA), characterised by gradual cooling and short-term weather anomalies that resulted in increasing incidence of harvest failures and food shortages for both humans and livestock. The rapid population growth in the two preceding centuries or so led to the Malthusian Crisis (overpopulation in relation to the available land resources), falling living standards, and growing poverty. The already dire situation was aggravated further by purely anthropogenic factors, such as market malfunctioning, taxation, and ongoing warfare, which resulted in the further dwindling of food resources. One clear outcome of this adverse combination of climatic deterioration, demographic pressure, and institutional setbacks was the occurrence of harsh subsistence crises, most notably the Great European Famine of 1315-1317, and Mediterranean famines of 1328-1329, 1333, 1346, and 1374-1375. When the plague arrived in Europe in 1347, it found an already weakened population, easily susceptible to pathogens.
A close analysis of the Semirech'ye data reveals clear signs of a society in crisis, which mirrors the situation in Europe. As some studies have shown, large-scale climatic deterioration, resulting in short-term climatic shocks and economic crises, dominated Central