Seleucid ambitions to occupy Coilē-Syria, which received a setback at Raphia, revived after the death of Ptolemy IV Philopator in 204 B.C. Under Ptolemy's infant son, the Egyptian court soon sank into an atmosphere of intrigue which facilitated the Seleucid invasion southwards in 202 B.C. (Polyb. 15.20; Hieron. In Dan. 11.13–14). Antiochus III failed to occupy Gaza, the last Ptolemaic stronghold in southern Palestine, during 201 B.C. (Polyb. 16.22a), and in winter of 201–200 B.C. he retired to Syria after setting up garrisons in key positions (see Map 10). The Ptolemies, however, did not give up: supported by new recruits from Greece (Polyb. 15.25.16; Livy 31.43.5–7), Scopas, the Aetolian officer serving as chief of staff in the Ptolemaic army, reoccupied Coilē-Syria in the winter of 200 B.C. (Jos. Ant. 12.131, 135; Hieron. loc.cit.). Antiochus' counterattack probably took place the following summer. The Egyptian army tried in vain to halt the enemy near the northern frontier, at Panion, and was defeated and scattered. Scopas himself, with 10,000 survivors, took refuge in Sidon (Hieron. op.cit. 15–16, based on Porphyrios), probably in the hope of being evacuated by sea, but the Egyptian navy seems to have been delayed, and Scopas had to surrender to Antiochus' besieging force. Thus the long struggle in Coilē-Syria was decided ultimately in favour of the Seleucids.

Unfortunately, the only extant account of the battle is an indirect report which has survived in the sixteenth book of Polybius (par. 18–19). Berating Zeno of Rhodes for what he calls his preference for rhetorical phraseology over historical accuracy, Polybius tries to illustrate his argument by criticizing the version presented by Zeno of the battle of Panion.

In the following years Demetrius did not abandon his desire to unify the Hellenistic world, which had been smashed to pieces at Ipsus. The second battle of Seleucus I for which we have a relatively detailed record, the battle of Cyrrhestica in 285 B.C., brought this hope and Demetrius' career to an end.

After losing Macedon, which had been his base of power, to Lysimachus and Pyrrhus in 287 B.C. (Plut. Demetr. 44), Demetrius escaped to Asia Minor with a small army of mercenaries, determined to recover his father's Asian Empire. At first he tried to stir the Ionian cities to rebellion, but the appearance of Agathocles, son of Lysimachus, compelled him to turn eastwards. His plan was now to reach Media, then under Seleucus' control, and with the help of the soldiers settled there by his father reconquer the east. But the troubles and hardship he met on his flight from Agathocles and the soldiers' refusal to set off on the long expedition to Media forced him to try to come to terms with Seleucus and ask him for a small territory on the northern slopes of the Taurus. After being turned back, and after some preliminary skirmishes in Cilicia, Demetrius played his last card. He invaded Syria and arrived at Cyrrhestica with his small mercenary force (ibid. 46–8; Polyaenus 4.7.12).

Antigonus, Ptolemy, and Seleucus, the first Hellenistic rulers in the east, were faced with an unprecedented politico-military dilemma when they turned their attention to the administration of their realms. The territories at their disposal were together more or less equal in size to the enormous dimensions of the Persian realm, but the Macedonian generals, unlike the deposed oriental kings, were an alien element in the area. They therefore had no local power base which would permit them to mobilize the indigenous population in defence of their territorial achievements, nor any outside the area, since Macedon itself was occupied by their rivals.

It has long been established that a solution to this problem was found in the settling of soldiers, mostly European by descent, on allotments of land in the newly occupied territories in return for certain military obligations. The ingenious concept of military settlements achieved two advantages: on the one hand it established islands of Greco-Macedonian population among the oriental natives, thus spreading the influence of Greek culture among the upper classes of the subjugated nations, and, on the other, it provided a reservoir of trained and loyal manpower that served mainly in the phalanx and was always ready for any call to duty.

After the relative abundance of information about the battles of Antiochus III, references to expeditions and military operations of his Successors are vague and given in general terms. Only the campaigns against the Jews are described in any detail but, unfortunately, only in Jewish sources, most of which do not match up to the historiographical standard of those discussed so far. Of all the campaigns against the Jews, the most detailed and interesting from the tactical point of view is the second expedition of Lysias to Judaea and the battle of Beith-Zacharia in 162 B.C.

Judas Maccabaeus had in the past frustrated four Seleucid attempts to invade Judaea (I Mace. 3.10–26, 38–4.35), and when Lysias abandoned his first expedition Judas reoccupied Jerusalem, purified the temple, and evacuated the Jews who lived in the neighbourhood of the Hellenized cities (ibid. 4.34–5.68). Although a part of the army was still stationed in the eastern satrapies (ibid. 6,7.55–6), Lysias decided to try once more to subdue the revolt, perhaps in order to establish his position on the domestic front. Antiochus V Eupator, aged 9 or 12 (App. Syr. 66; Euseb. I p.254), also took part in the expedition (I Mace. 6.28ff.).

As he had already done on the previous expedition (I Mace. 4.29), Lysias avoided the dangerous passes to the Judaean plateau on the north and northwest, which were surrounded by a hostile Jewish population, and took a southwestern route, which passed through the territory of the Edomeans who supported the Seleucids against the Jews.

The delimitation of subject expressed in the title requires comment. There were many tenants on public land as well, some under legal and economic conditions comparable to those of tenants on private holdings. But the public hand introduced an additional element, at least de facto, that can only confuse the discussion, and on many imperial estates (which are examined in an earlier chapter) there were tenancy arrangements for which private parallels are unattested and, in the nature of the case, impossible. The most obvious example is the ‘Mancian tenure’ in North Africa, which, as it happens, constitutes the bulk of what we know today about tenancy on imperial estates, apart from Egypt. My concern is with one of the two ways that Roman owners of large landholdings exploited them – the other was of course ‘direct’ exploitation by slaves under a vilicus – and that can be studied only by exclusive concentration on private owners.

Restriction to Italy has a double explanation. First, the conditions and the rules in various parts of the empire differed greatly, chiefly because the Roman conquerors did not normally overthrow existing institutions, so that Roman Egypt, for example, was in this respect more like Ptolemaic, or even Pharaonic, Egypt than like Italy. Egypt provides by far the fullest and most detailed documentation, but for extremely short leases, one to three years, within a legal system which, however one chooses to label it, was not Roman, and within an inexorable irrigation system wholly alien to Italian, or European, experience.

The breakthrough at the Porphyrion Pass opened the way for the invasion of Coilē-Syria by the Seleucid troops. After systematically winning control over the various regions, Antiochus retired to winter quarters at Acre (Polyb. 5.71.12). The Ptolemaic army, which had deteriorated through being idle for about a generation, was reassembled in 219 B.C. and subjected to intensive training (ibid. 63–5). When the preparations were completed, in June 217 B.C. (Gauthier–Sottas, pp.34. II.10–11), Ptolemy IV made a forced march of five days to southern Palestine and encamped 50 stadia to the southwest of Raphia. Antiochus, hearing of the enemies' advance, left Acre and proceeded with speed along the coastline via Gaza to Raphia (ibid. 80.3–4). The Ptolemaic victory in the battle settled the dispute over Coilē-Syria for another 17 years.

The sources for Polybius' detailed account of the battle (5.79–85) are uncertain. While Momigliano considers them to be pro-Ptolemaic and suggests Zeno of Rhodes as Polybius' direct source, Otto and others, who lay much stress on the recurrence of comments on Ptolemy's love of luxury and indifference to external affairs (5.87.3,7; cf. 34, 42.4, 62.7, 107; 14.12.2–3 et passim), prefer to regard Polybius' sources as pro-Seleucid. But it is doubtful whether Seleucid sources would have so described the king who in so decisive a manner defeated Antiochus III, given the appellation ‘the Great’ a few years later. On the other hand, the indications of a ‘Ptolemaic’ source are much more impressive: Ptolemy's secret military preparation are recorded in detail (5.65–8); Ptolemy's personal appearance in the ranks of the phalanx is credited with inspiring his troops and lowering the morale of the enemy (85.8).

With the settlement of the eastern problem and the occupation of Coilē-Syria, Antiochus III was now free to turn his attention to the Aegean world. His operations in the area soon brought him in conflict with Rome. Diplomatic negotiations failed to achieve an agreement, and Antiochus, disheartened by the toughening of the Roman policy, yielded to the promises and enticements of the Aetolians, incited by the overthrow of the pro-Roman faction at Demetrias, to ‘liberate’ Greece and thereby possibly improve his bargaining position. Antiochus had at his disposal in Asia Minor only about 18,000 troops (see p. 18 above), but he crossed the Aegean hastily at the beginning of the winter hoping to receive support, especially from the Aetolians and Philip V. In the first months of his stay in Greece he engaged in an exhaustive diplomatic and military campaign to make sure of allies for the expected confrontation with the Romans. But the Roman invasion came too soon: 20,000 infantry, 2,000 cavalry, and 15 elephants crossed to Greece from Brundisium in the early spring (Livy 36.14.1; App. Syr. 15(65)). Antiochus was caught unprepared: the bulk of the army, especially the cavalry, was stranded in Asia; part of his landing force was scattered over Greece in garrisons, and a number of them surrendered to the Romans. Worse, the expected local help did not materialize: Philip V sided with Rome and the Aetolian auxiliary numbered only 4,000 infantry. At this stage Antiochus had 10,000 infantry, 500 cavalry, and six elephants of his own (Livy 36.15.3). In these circumstances he had to rule out a confrontation on the open field.

When in A.D. 193 Pertinax was appointed emperor as a senatorial candidate, he faced the problem presented to each new Roman dynasty of what attitude should be taken to its predecessor's personal possessions. Of these land was one of the most important. Pertinax' reaction, if we may believe Herodian (2.4.1–7), was both novel and positive. His own name was not to be given to imperial possessions which belonged rather to the whole Roman people and, in an attempt to bring uncultivated areas of the empire back into production, he proposed to offer ten years' tax remission to those who would undertake their cultivation, to be followed by outright possession of the land, including that which was previously imperial.

Few emperors shared the scruples of Pertinax and the passage is controversial (see chapter 8); but the proposals of Pertinax may be used to illustrate the issues with which I shall be concerned in this paper: firstly, the definition of imperial estates; secondly, their movement in and out of imperial control; thirdly, their management, both separately within the estates and more generally on a provincial level within the overall economy of the empire; and finally, the involvement of the emperors with their estates. The main limitation will be that imposed by the evidence, which inevitably gives an incomplete and somewhat erratic coverage by both period and province. It is nonetheless important to concentrate on those estates actually attested as imperial and to exclude land merely thought to be imperial. I have attempted to collect the chief sources for attested imperial estates in the Appendix but such a list inevitably remains provisional.

After his defeat at Raphia, Antiochus III concentrated on recovering Asia Minor. Having succeeded in capturing Achaeus and bringing the rebellion to an end in 214 B.C., he turned to the pursuit of his great dream: the reestablishment of the territorial dimensions of the Empire in the time of Seleucus I by means of a forceful anabasis to the east. Only a few fragments of Polybius refer to this great expedition and include some account of military operations (10.28–31, 48–9). The most interesting is the detailed description, based probably on eyewitness accounts, of the crossing of the Elburz range on the way from Hecatompylus to Hyrcania, which demonstrates the march order and tactics of Antiochus III in difficult mountain passes (28–31).

Antiochus' route has been identified as the central pass of the Elburz range leading from Shahrud through the Chalchanlyan Pass to the Chasman – Sawer valley, and from there through the Quzluq Pass to Astrabad (Gorgan, see Map 9). The main part of the route follows a riverbed which enters a narrow and precipitous gorge with cliffs soaring some 800–1200 m above the defile about 6 km from the Chalchanlyan Pass (30.2), a circumstance which led Antiochus to fear an ambush either by local tribes or Arsaces! troops. His anxiety was increased by Arsaces' reluctance to join battle, even near Hecatompylus, which was ideal for cavalry warfare, in which the Parthians obviously had a considerable advantage.

Estimates of the numerical strength of armies are of doubtful validity in ancient historical literature and indeed in accounts of modern warfare even as late as the eighteenth century. Commanders-in-chief and official chroniclers have combined to obscure the truth by underestimating the number of their own troops and overestimating that of the enemy's. Greek historians from Thucydides onwards achieved admirable precision and objectivity in estimating the number of troops on their side, which is in striking contrast to the utterly unreliable figures given in oriental literature, but even they are of little value whenever there is reference to the Persian armies, whose size is wildly exaggerated even by the trustworthy and experienced eyewitnesses of Alexander's anabasis. The modest figures quoted for Greek armies during Classical times increase abruptly with Alexander's expedition and become still larger in the armies of the Diadochs, but this is explained by the dimensions of the undertakings, the economic resources then available, and the system of recruitment. Alexander won the day at Gaugamela with 40,000 infantry and 7,000 cavalry (Arr. Anab. 3.12.5), but by the time of the battle of Ipsus a record had been set with approximately 80,000 on either side (Plut. Demetr. 28.3), and, as will be seen later, the tendency towards ever greater numbers of soldiers was more prevalent in the Seleucid armies than among their contemporaries. Nevertheless, since the figures quoted for the Seleucid campaigns are not always derived from first-class sources, they require careful examination.

Seleucus I's intensive military activity after the occupation of Babylonia in 312 B.C., which laid the foundations of the Empire, is recorded only once, and this is in the account of his part in the battle of Ipsus (301 B.C.), which decided the dispute over Alexander's domain between Antigonus and his son Demetrius, who were in favour of unification, and the former generals Lysimachus, Cassander, Seleucus, and Ptolemy, who preferred to see the Empire divided among themselves. Although Seleucus' troops, who actually won the day, comprised only one part of the Allied army, which was mainly based on Lysimachus' infantry and a detachment sent by Cassander, the course of the battle, unique as it was, is reminiscent in its general outline of the tactics of the later Seleucids.

In fact only part of the battle can be reconstructed. The main source, Plutarch in his biography of Demetrius (28–30), focuses his interest, as may be expected, on Demetrius' activity and the tragic fate of Antigonus, paying scant attention to the military manoeuvres. His dramatic treatment of the event and its tragic features indicate that he relied here, as in other biographies, on Duris of Samos, whose emotional and sensational style must be approached with caution. But even if Plutarch had based his account of Ipsus on Hieronymus of Cardia, an eyewitness and experienced soldier whose report was certainly excellent, Plutarch's own lack of understanding of military affairs, his frequent distortion of reliable military authorities, and his tendency to impose his own conception of his hero's character on the facts, must be borne in mind when evaluating his interpretation. Diodorus' version, presumably paraphrasing Hieronymus of Cardia, was lost.

For two years our research seminar examined various aspects of Roman property. Some twenty people participated regularly and another ten or twelve attended when they could, not all from Cambridge. Several of the topics discussed are not properly, or not at all, represented in this volume: the more obvious absentees are land-values and methods of valuation (including sale by auction and the relationship between rents and prices) and the link between land and debt, generally as well as in the publicized crises of 49 B.C. and A.D. 33. The decision to publish or not was an individual one, depending solely on the author's personal judgement, whether because the investigation of a particular topic had been completed or because a survey of the current state of our information was a clear desideratum or because a neglected aspect of Roman property needed to be brought to the fore for further research.

Not only was every chapter discussed in the seminar but subsequent drafts were read and criticized by individual participants. This volume therefore represents common work (hence no thanks are expressed in the notes to members of the seminar) but not collective work. That is, no doctrines or agreed conclusions were imposed, or even sought, though there was fairly general agreement about the questions to be asked. As a result, though some disagreements were resolved, either in the seminar or in private discussion, others remain. Editorial intervention was restricted to the elimination of excessive duplication and overlapping.