How? the perimortem trauma pattern

By studying the positions of the unburied skeletons at Sandby borg in tandem with the perimortem trauma, it is possible to obtain additional information about the modus operandi of the perpetrators.

In total, eleven perimortem lesions were identified in eight individuals. Sharp force trauma was documented in seven cases, blunt force was used in two cases, and puncture wounds were caused in two cases (Table 2). Two individuals (ID1 and ID3) suffered at least two sharp force blows. Bones of the cranium were the most affected, suggesting that this was the primary target, but postcranial wounds were noted in the neck (cervical vertebra(e)), shoulder (scapula), and hip region (the ilium) of the individuals, with no preference as to which side of the body. The blunt injuries were located on the top of the head, near the sagittal suture, whereas the wounds inflicted by sharp objects varied in location and direction. Of the eleven perimortem lesions identified, five were aimed at the back of the body (scapula, ilium, femur, and two on the occipital) of the victims, implying that they were attacked from behind. The trauma identified in the cervical region of ID13 could perhaps also be included in this group. The lesions on top of the cranium of at least ID1 may indicate that the individual was in a lower position in relation to the perpetrator, or that the latter was on horseback (that scenario is however very unlikely given that the skeleton was found indoorsFootnote ¹). Only two of the lesions (on ID 3 and ID14) are consistent with battle wounds that could be expected in face-to-face combat with a right-handed assailant (Larsen, Reference Larsen1999: 157). However, there might be an under-representation of facial trauma identified since the preservation of the delicate facial bones was poor. Characteristic defence injuries, such as parry fractures on the forearms or hands, or sharp incisions on the palmar aspect of the finger bones, are missing (Dolinak et al., Reference Dolinak, Matshes and Lew2005: 149–50).

Moreover, the bodies of the remaining individuals who do not have observable perimortem lesions were also found in the dwellings and in the street (Figure 5). They were discovered in a flexed position (ID7, figure 5A) and lying extended, both prone (ID9) and supine (ID 5 and ID12, the latter in figure 5B), and possibly sitting (ID15). In one case, individuals had fallen over each other (Alfsdotter et al., Reference Alfsdotter, Papmehl-Dufay and Victor2018). An older man (ID9) was lying face down diagonally over the central hearth of House 52. The anterior pelvic region was partially charred, suggesting that the fireplace was still burning, or at least smouldering, when the man fell (Papmehl-Dufay & Alfsdotter, Reference Papmehl-Dufay and Alfsdotter2016).

Figure 5.

A: The articulated skeleton of ID7, an adolescent, is one of nine individuals whose remains have been found inside House 40. B: The partially articulated skeleton of a child (ID12) excavated in House 4.

Although the number of identified injuries is low, the varied distribution lacks patterning, which implies that the victims did not carry any protective gear (this is hardly surprising given the demographic spread). This is in line with the general impression that the inhabitants were taken off guard. If the trauma analysis is representative of a massacre, the preferred weapon of the assailants was the sword. It is not possible to rule out axes; but, as none of the sharp force lesions exhibit the fracture pattern expected from a combination of sharp and blunt force trauma caused by an axe (Reichs, Reference Reichs and Reichs1998), swords were most likely to have been the weapon used. The penetrating lesion did not have enough characteristic traits to identify the weapon type, and could have been caused by any sharp, pointed weapon (such as a spear or lance) or other object. The same goes for the blunt force traumatic injuries.

By combining the perimortem lesions with body positions, it may be possible to establish the circumstances surrounding the deaths of certain individuals. The supine skeleton of individual ID1 had three injuries where the sharp force trauma on the scapula must have severed the muscles of the right rotator cuff (teres minor, supraspinatus and infraspinatus). This impaired the stability and movement of the shoulder and upper limb. The blow does not seem to have penetrated the posterior thorax. The penetrating wound on ID1's femur could, in a similar way, have damaged muscles and tendons (musculus biceps femoris and tractus iliotibialis). Both lesions must have led to blood loss but need not have been lethal. The cranium, however, shows a wound which penetrated the inner table of the parietal bone, exposing the brain tissue. The sequence of the lesions is hypothetical, but it is likely that the blow to the back and thigh preceded that on the head since the latter caused severe cranial damage which could, in itself, have resulted in the death of the man. Consequently, it is possible that the man managed to survive an initial blow, before being struck on the head and falling on his back. In another house, the skeleton of the 10–13 year old adolescent (ID13) had SFT in the neck region. Though the cervical vertebra(e) are severely fragmented, it is clear that at least one horizontal blow cut through the soft tissue and penetrated the medulla, which would have damaged major arteries (posterior inferior cerebellar artery and possibly anterior spinal artery). The cut(s) are likely to have led to the instant death of the individual at the site where the human remains were discovered (if they were not moved secondarily). These two case studies suggest that, at one point, the wounded shared space with the dead and dying, illustrating a chaotic situation with people in a state of shock. Perhaps ID1, who died just inside the entrance of House 40, was wounded in the street, after which he entered the house (for shelter?) where he then received the final blow to his head.

Who? trauma and demography

The isotopic data (Wilhelmson, Reference Wilhelmson2017) indicate that at least two of the Sandby borg victims grew up in the region. Whether this is true for the rest of the group is not yet known, but it is likely that the youngest victims of the massacre were born on the island. Moreover, it is probable that all the victims were local inhabitants. Only male remains have been identified among the adults for whom sex could be determined. The presence of an infant and young children, and the finds of female attire (Magnus, Reference Magnus, Webster and Brown1997, Reference Magnus and Høilund Nielsen2002), imply that women lived within the walls. Within the bioarchaeological field, there are examples where a biased sex distribution (with no or few women) in a skeletal collection has been interpreted as raiding for women and girls. This practice is not uncommon in attacks on small settlements (e.g. Kohler & Kramer Turner, Reference Kohler and Kramer Turner2006; Cameron, Reference Cameron2013; Martin & Harrod, Reference Martin and Harrod2015). Although the main purpose of the attack was not necessarily to take prisoners, the kidnap of women may have been an added benefit. They could be taken as wives, used as extra labour, or sold as slaves (e.g. Martin et al., Reference Martin, Harrod and Fields2010). However, since only a small part (c. 9 per cent) of the ringfort has been excavated, the absence of female remains could be a coincidence, and we must be wary of over-interpreting this aspect. It should also be stressed that the sex distribution among the children is yet to be established through DNA analysis. Nevertheless, it is not uncommon that women are treated differently in massacres, and perhaps the female remains are to be discovered in another part of the ringfort.

If we consider the taking of slaves as a possible reason behind the attack, this is complicated by the presence of children and teenagers, who we may assume were easy prey. Could the children have taken part in the battle? Little is known about the socialization processes of children during the period, and it is not clear when a child was considered to have become an adult. The transition from childhood into adulthood was likely to have been based on physical and mental maturity, but could also be connected to the social status of the individual (Mejsholm, Reference Mejsholm2009: 24). For boys, it could be associated with a time when the youth was physically fit for weapon training. The youngest individuals at Sandby borg with documented perimortem injuries were the decapitated 10–13 year old adolescent (ID13), and a 12–15 year old (ID6) with a blunt force lesion to the right parietal (Tables 1 and 2). The sexes are not known, and it is not clear whether these individuals were passive victims or if they put up armed resistance. Attempts to identify active engagement of non-adults in violent encounters have been made in prehistoric skeletal assemblages (Fibiger, Reference Fibiger, Knüsel and Smith2014). Adolescents of similar age to those found in Sandby borg were assessed as having probably participated in armed conflict in early medieval Ireland (Geber, Reference Geber2015). Even if this were the case with the two young individuals from Sandby borg, the younger children were either deliberately killed (but without lesions identified) or left to die. This indicates that the killings were indiscriminate with regard to age. Furthermore, the young individuals (twelve of the twenty-six individuals were younger than 15 years old) could not, if we disregard the signs of visible trauma, have had much, or any, battle experience. At the other end of the age spectrum, there were three men older than 50, none of whom had identifiable antemortem or perimortem wounds. Both groups could be seen as ‘atypical warriors’.

The remaining group (n = 12) of young or adults in the category ‘middle adult’ may be considered able-bodied and fit for fighting. Indeed, it is this group that exhibits the highest number of perimortem lesions, and it is tempting to interpret these visible weapon wounds as indicative of a more active resistance to the attack. However, the biased distribution of wounds could be due to preservation factors. At any rate, only one or two individuals in this group (ID1 and F6671) show signs of healed direct fractures, and the number of antemortem traumatic injuries was generally modest in the Sandby borg skeletons. The prevalence is similar to that found in contemporary cemetery populations. For instance, c. 8 per cent of the individuals (both men and women) in the Migration-period cemetery of Prague-Zliín, Czech Republic, showed traces of healed traumatic lesions (Vargová et al., Reference Vargová, Horáčková, Horáková, Eliášová, Myšková and Ditrich2016). A high frequency of antemortem trauma may indicate previous battle experience. In the study of the skeletal remains from the Battle of Towton (England), for instance, at least 32 per cent of the crania exhibited healed, weapon related lesions, implying experience of previous encounters (Novak, Reference Novak, Fiorato, Boylston and Knüsel2000). Overall, the demographic composition, along with the trauma pattern, shows that most individuals exhumed in Sandby borg had little chance to defend themselves, and that only a few are likely to have had battle experience. Although grown men were probably the primary target group, all members in the Sandby borg community seem to have been subjected to violence, and non-combatants could at least be considered collateral damage (see Tegtmeyer & Martin, Reference Tegtmeyer, Martin, Martin and Tegtmeyer2017). The deliberate killing or abandonment of young children further suggests that the intention of the attack was to annihilate the inhabitants. Though it is possible that some of the fallen adult men belonged to the attackers, it appears unlikely that the assailants would have left any of their own behind, as the victorious group in a battle normally has the opportunity to tend to their dead.

Does the trauma pattern at Sandby borg and the identification of weapon injuries reveal anything about the assailants? It has been suggested that Scandinavian men could have received military training in the Roman Empire (Nicklasson, Reference Nicklasson1997: 173; see online supplement: Supplementary Material 1). At least in theory, formal training with weapons could lead to ‘standardized’ violence, a recognizable pattern with regard to injuries sustained by the victims. However, no such injury pattern was discernible, since the small size of the sample and the poor preservation of the remains has affected the outcome of the analysis. Given the few perimortem traumatic injuries identified, the same can be said about the primary choice of weapon, thought to be the sword. In close combat, this is the most effective weapon; but, as discussed, other types of weapons, pointed, edged, or blunt, could also have been used.

Why? contextualization of trauma and the inhabitants of Sandby borg

Martin and Harrod write that massacres (i.e. multiple killings of all age groups and of both sexes) can be seen as a political instrument that is ‘[…] often used by perpetrators to either subjugate or eradicate a group defined as having cultural characteristics that separate them in some way from the aggressors’ (Martin & Harrod, Reference Martin and Harrod2015: 129). Since interpersonal violence is seldom random, it allows the perpetrators to gain control over land or other groups. The competition for women can be a contributing factor behind conflicts in both prehistoric and present-day small-scale societies (Sanderson, Reference Sanderson2014: 291–96); although groups demonstrate a great variability regarding the causes of violence (McCall & Shields, Reference McCall and Shields2008). Furthermore, massacres are part of complex processes, not only because they imply planning and the involvement of many people, but also because they operate at a sociopolitical and cultural level. Environmental stress factors and risk of losing resources could also be a motivating factor for violence (Ember & Ember, Reference Ember, Ember, Martin and Frayer1997). Studies of different geographical regions, dating from 10,000 bc to today, have shown that there is a strong relationship between climate change and intergroup conflict (Hsiang et al., Reference Hsiang, Burke and Miguel2013). This is interesting, since tree ring data has shown that the period ad 450–550 in Europe was a time of climatic changes (Büntgen et al., Reference Büntgen, Tegel, Nicolussi, McCormick, Frank and Trouet2011). It is difficult to establish to what degree a small-scale society like that at Sandby borg would have been affected by fluctuations in temperature and precipitation and what specific social stress factors could have led to the Sandby borg massacre. A combination of several factors was probably at play.

A change in settlement pattern can be seen in Scandinavia during the Migration period, where several settlements were abandoned or destroyed. This has been interpreted as a socioeconomic crisis, possibly related to changing political structures in the aftermath of the fall of the Western Roman Empire (e.g. Stenberger, Reference Stenberger1933; Näsman, Reference Näsman, Näsman and Lund1988; Fischer, Reference Fischer2005; Heather, Reference Heather2006; Hedeager, Reference Hedeager2011; see also discussion in Alfsdotter et al., Reference Alfsdotter, Papmehl-Dufay and Victor2018). The presence of dead children at Sandby borg may be indicative of extraordinary circumstances. Non-accidental perimortem injuries documented among young children from the fourth–fifth-century ad cemetery of Lisieux in Normandy in France have previously been interpreted as the result of social stress caused by political disturbances and perhaps raiding groups (Timmins et al., Reference Timmins, Seréville-Niel and Brickley2017). In another study, in the context of the fifteenth-century massacre of Čepin in Croatia, bioarchaeological results were used to identify the causative agent behind a specific raid, and to differentiate attempts to take prisoners of war from attempts to strategically spread fear and panic in a population (Šlaus et al., Reference Šlaus, Novak, Vyroubal and Bedić2010). Judging from the current analysis of the Sandby borg assault, it is unlikely that the massacre was the result of an attempt to obtain wealth, since potential prisoners (e.g. children), luxury items, and animals were left behind. Theoretically, the attack on Sandby borg could have been some form of retribution. In discussing violent behaviour and its aftermath during the Iron Age in Scandinavia, Lindbom (Reference Lindbom2006: xviii) suggests that an attack on a farm (i.e. attacking people in their home) was an extreme act with dire consequences. The attackers were consequently forced to kill everyone to eliminate witnesses and, thus, avoid being subjected to vengeance. So far, there is no archaeological or osteological evidence of feuding between Sandby borg and other local groups (e.g. evidence of burning in cultural layers caused by previous fires, large collections of weapons, or healed weapon-related trauma).

In skeletal series associated with contexts similar to those of Sandby borg, bioarchaeological analyses have revealed information about the extent of the violence. In well-known cases of attacks on villagers in other periods and geographical regions, documented for example on prehistoric and historic sites in the US, dreadful acts of violence, such as mutilation and trophy-taking, have been documented (e.g. Owsley et al., Reference Owsley, Berryman and Bass1977; Willey, Reference Willey1990; Andrushko et al., Reference Andrushko, Latham, Grady, Pastron and Walker2005). Acts of body processing in a ritual or sacrificial manner have also been observed in Iron Age wetland contexts, showing that postmortem manipulation of human bodies was not a completely uncommon or extreme behaviour (see Supplementary Material 1). However, the scene at Sandby borg suggests a different situation. The attack appears to have been an expedient and brutal affair. The villagers were seemingly taken by surprise rather than engaged in a conventional battle. Although it is impossible to say anything about how much has been plundered, the perpetrators do not appear to have been very interested in staying and searching for loot, considering the quantity of jewellery and other luxury items found during the excavations. The injury pattern and the positions of the bodies is another indication of a brief attack. The victims do not have the appearance of having been moved after they died, and the injuries are almost ‘efficiently’ distributed, in the sense that only the minimum amount of violence necessary to kill was used (for a taphonomic analysis, see Alfsdotter & Kjellström, Reference Alfsdotter and Kjellströmin preparation). The comparatively few instances of perimortem fractures (even in the rather complete skeletons, e.g. ID7 and ID12) suggest that each victim was overcome with a minimum of effort by the attacker. The injury pattern and reconstructed body positions also indicate that the victims’ bodies were not further brutalized or manipulated after death. Furthermore, the repeated pattern, with dead humans inside and outside several houses, suggests that the perpetrators were numerous and coordinated.

Dutton et al. (Reference Dutton, Boyanowsky and Bond2005) explored the varying motives behind massacres and genocides during the twentieth century. Although the social systems of modern states and small Iron Age chiefdoms differ greatly, some arguments put forward in this study may be pertinent to the discussion of the motives behind the Sandby borg massacre. A common denominator of mass killings is that the perpetrating group perceives the target group as having obtained some form of unfair advantage. Historical and political circumstances affect the identification of the target group, and the mass killing is legitimized among the perpetrators as revenge (Dutton et al., Reference Dutton, Boyanowsky and Bond2005: 470). Often, mass killings are the result of feared future conflict, and rapid social change is frequently behind the perception of a threat that must be eliminated. When indiscriminate killing takes place (e.g. of children), the actions are often justified on the basis that the target group poses a future threat. A plausible alternative (or additional) motive can be to cause terror through the ruthless killing of vulnerable individuals. The excessive violence commonly witnessed in massacres (mutilations, rape, torture, and killing of defenceless victims) differs from the violence often seen in genocides, where the violence is ‘dispassionate’ and ‘instrumental’ (since the violence is carried out by those who only execute orders) (Wolfgang, Reference Wolfgang1958; Dutton & Kerry, Reference Dutton and Kerry1999). Dutton et al. (Reference Dutton, Boyanowsky and Bond2005) argue that sociopolitical circumstances may be enough to explain instrumental violence, whereas the ‘passionate’ killing seen in many massacres is not yet well understood. If we combine theories of modern mass killing with the efficient slaughter so far evidenced in Sandby borg, it is plausible to interpret the dispassionate killing as having been caused by sociopolitical instability. The lack of traces of overkill combined with the effective killing pattern could indicate that the individuals who carried out the slaughter were not personally involved with the victims. Possibly, the killing was ordered. Credible motives behind the massacre were likely to have been connected to experienced past injustice, the perception of the Sandby borg inhabitants as a threat, and the will to spread fear to achieve control. This hypothesis fits with the interpretation that the massacre in Sandby borg was not a raid carried out for the purposes of plundering. The motives suggested point to the attackers having been a neighbouring group (also discussed in Victor, Reference Victor, Arnell and Pamphell-Dufay2015; Alfsdotter et al., Reference Alfsdotter, Papmehl-Dufay and Victor2018). Though a ‘personal’ scenario cannot be verified based on the current analysis, and remains speculative, the unburied bodies appear to signal a provoking motive. They could be seen as a final act of violence, and even that the entire community was wiped out. The finds at Sandby borg strengthen the perception of the Migration period on Öland as a socially turbulent time, probably involving strife with conflicting groups of inhabitants.

The proposed mass killing at Sandby borg can be contrasted with the image of warfare associated with finds such as the weapon deposits in Hjortspring and Nydam in Denmark (see Supplementary Material 1). The weapon offerings are deposited in an organized and orchestrated form, demonstrating control and power in relation to the contemporary narrative and ideology. At Sandby borg, the grim result and reality of violence is evident.