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.

The abortive invasion of Greece, which revealed Antiochus as an open and declared enemy of Rome, made necessary military intervention to back up Roman demands for the evacuation of Thrace and the Ionian cities. Antiochus at first tried to fortify the Hellespont against the expected crossing by Roman expedition, but, after losing control over the Aegean in the naval battle of Myonnesus (off Teos), he realized that the naval supremacy of the Romans would enable them to bypass his land fortifications in the Dardanelles, and he abandoned them. After the failure of further negotiations, both sides were determined to seek a solution by arms. Antiochus mobilized his army from Sardis along the Hermos Valley to Magnesia-ad-Sipylum against the Romans, who were advancing from the Pergamon area to Thyateira in the Hyrcanian Plain, and thence along the Phrygios southwards. Magnesia, which in 281 B.C. had been the site of the battle of Curupedion, which was decisive in opening the way to the west for the Seleucids, was now to see the beginnings of Roman expansion in the east and Seleucid decline.

The main sources for the battle are the parallel versions of Livy 37.37–44 and Appian Syr. 30–6, based solely on Polybius, who himself made extensive use of Rhodian, Achaean and Pergamene sources, probably in addition to reports from eyewitnesses.

After a gap of more than 50 years for which there is little documentation, information about Seleucid activity in the battlefield becomes available again with Polybius' account of the decisive battle against Molon (5.48.17–54), which opens a series of battle accounts covering Antiochus Ill's reign.

Molon, the satrap of Media, revolted in 222 B.C. shortly after Antiochus Ill's accession, crowned himself king, and took possession of all the eastern satrapies. Antiochus, who at first concentrated his efforts on the southern frontier, contented himself with sending relatively small expeditions under second-rank generals to prevent Molon from occupying Babylonia (Polyb. 5.41–2, 5, 43.5–45.7, 46.6–48.16). But when the various expeditions had all been defeated, and Molon had taken control of much of Mesopotamia, Antiochus himself was compelled to assemble all the royal troops and lead them in a decisive confrontation with the rebel.

At the beginning of the campaign Molon was in winter quarters near Seleucia-upon-the-Tigris (48.15–16, 52.6). Antiochus marched swiftly across Mesopotamia and arrived at Apollonia, identified as Baradan Tepe, close to the junction of the Diala and the Narin Tchai (see Map 4). Molon was informed too late about Antiochus' drive, and, decamping in haste, set out for the hilly region of Apollonitis on his way to Media.

Some of the strategy of both sides is outlined by Polybius. Antiochus was eager to block Molon's way back to Media, which passed through Apollonitis, and was anxious to control this fertile region, which would give him a firm logistic base if Molon tried to play for time (51.8–11).

The dominant place of the land in the economy and society of classical antiquity is a commonplace. Yet no synoptic view of the subject has been attempted in the past half-century, none on Rome alone for more than eighty years. This book does not pretend to fill that gap. To begin with, a narrow focus was selected for the inquiry, which may be defined crudely as Roman investment in property. That ruled out some of the best known aspects of the larger theme, such as land tenure or the history of the ager publicus during the Republic – not because these are less important aspects but because, for intensive cooperative study, it was necessary to restrict the field to something which would be manageable (given our limited resources) and yet permit us to look at the same questions from several viewpoints. That is also why slavery was taken for granted, so to speak, and not investigated except as it had to be set against tenancy, for example.

Just what the notion of ‘investment’ meant in Roman society is one of the subjects of the inquiry: no presuppositions about maximization of income and the like were implicit in the choice of the word. Nor, in so far as that was possible, did we start from, or even give much attention to, the familiar and explicit Roman value judgements on the subject of land, whether in Cato or in Cicero or in anyone else.

After the suppression of Molon's revolt, Antiochus III diverted his attention to the Ptolemaic frontier in his bid to occupy Coilē-Syria. Polybius devotes to these efforts a considerable part of the Asian section in the fifth book. After two abortive attempts to break through the Ptolemaic forts guarding the Marsyas Valley, the central route from Syria to Palestine, which passes between the Lebanon and Anti-Lebanon (45.1–46.5, 61.3–62.6), he chose the more difficult, coastal route. The narrow pass and the steep cliffs that extend in several places almost to the water-line could be easily defended by the Ptolemies. But Antiochus was able to count on Tyre and Acre in the Ptolemies' rear, which had earlier come over to his side after the defection of Theodotus the Aetolian, the Ptolemaic mercenary-officer.

The main Ptolemaic defence was concentrated near Porphyrion, identified with the ruins in the triangle between Khan Nebi Younes and the villages Barja and Jiye, near Ras Nebi Younes, 25 km south of Beirut, and the battle is said to have taken place in the nearby narrow pass (see Map 6). Abel located the battle in Ras El Sadiyatt, 4–5 km to the north of Porphyrion, but Ras Nebi Younes, which is nearer Porphyrion, seems to be more suitable: Ras El Sadiyatt is 500 m to the south of the river Damouras (Damour), mentioned as the place where Antiochus camped before the battle (68.5), and, had the battle taken place nearby, it would naturally have been called after the river (cf. the fords of the river Lycus mentioned in the report of the same expedition, 68.9).

The Jewish rebellion, which sustained a bad setback from the heavy blow received at Beith-Zacharia, soon recovered its momentum, taking advantage of the internal crisis in the Empire and the struggle for succession at Antioch. Once established on the throne, Demetrius experimented with a new policy by granting Judaea the status of an eparchy, and appointing Nicanor, a high-ranking officer who formerly served as elephantarch, as the stratēgos of the new eparchy (II Macc. 14.12). But Judas Maccabaeus, encouraged by the confinement of the bulk of the Seleucid army in the eastern provinces in the expedition against the rebel Timarchos, defeated Nicanor twice in the battlefield. Nicanor himself was killed in the battle of Adasa and his body was displayed to the public in Jerusalem and mutilated (I Macc. 7.31–50; II Macc. 14.15–25, 15). The Hasmoneans resumed power all over Judaea after the victory. There was certainly nothing new in this development, but the Jewish treaty with Rome, which made imminent the danger of Roman intervention (I Mace. 8.17–32, esp. 31–2), forced Demetrius to react promptly and vigorously. After subduing the revolt in Babylonia (see p.210 n.29 above), he sent to Judaea Bacchides, who in his absence was in charge of the western regions of the Empire, in a determined effort to put down the Jewish revolt once and for all.

The history of the Seleucid army embraces a period of more than 200 years during which the kings carried on campaigns of different kinds against competitors in the Hellenistic world such as Lysimachus and the Houses of Ptolemy and Antigonus, barbarian invaders like the Galatians, rebels like Hierax, MoIon, Achaeus, and Timarchus, subject nations like the Jews and the Persians, and the two rising powers, the Romans in the west and the Parthians in the east, who finally divided the Seleucid domain between them. Some of these conflicts had far-reaching historical implications: the victory over Antigonus destroyed all hope of unifying the Hellenistic world and weakened its ability to meet challenges; the battles at Thermopylae and Magnesia heralded the shift in power in the Mediterranean from east to west; and the abortive attempt to suppress the Jewish religion deeply influenced the evolution of new religious beliefs and standards which left their mark on western civilization for many centuries.

The two outstanding features of the Seleucid army were, on the one hand, its quantitative and qualitative superiority over other Hellenistic armies, and, on the other, its inability to withstand the Roman army. In order to understand the first phenomenon, one must examine the organization of the Seleucid army, trace its sources of manpower, and ascertain the way in which its availability and military standards were maintained. These factors, in conjunction with the tactics and operations of the armies on the battlefield itself, may reveal the defects of the best of the Hellenistic armies when compared with the Roman legions.

When historians of the Roman economy write of investments in land, they normally have in mind rural property. The role of investment in urban property in the economy is seldom discussed. Moreover, what little has been said on the subject suggests that its significance is inadequately understood.

The standard works on economic history might be expected to place urban property firmly in its economic context. Tenney Frank recognizes the following sources of income for wealthy Romans in the late Republic: commerce and trade, provincial investment and moneylending (Pompey, Brutus, Atticus), managing and enlarging an inheritance (Atticus, his landowning and industrial concerns, inter alia), dealing in real estate, the legal profession, acting, and provincial government. Urban rents are not on the list. Rostovtzeff writes of the local aristocracy of Italian cities in the first century B.C. in the following terms: ‘Most of them were landowners, some were owners of houses let at rent, of various shops; some carried on moneylending and banking operations.’ Here acknowledgement is made of the relevance of urban property to the matter of the sources of wealth of the propertied class. But the reference is an isolated one. When, for example, Rostovtzeff enumerates those investments supposedly favoured by the new rich, the items mentioned are rural property, moneylending and Italian industry. Either it is by a mere oversight that urban property is omitted here, or we must conclude that in Rostovtzeff's view urban property was not taken at all seriously as an economic investment.

A high standard of training and discipline was a prerequisite for the tactical success of the military organization just described, but we can glean information about it from only a few scattered sources, which refer only to certain aspects. They can scarcely be said to paint a vivid picture, so that one has to be content with a general impression, keeping in mind that some references may apply only to a certain campaign and commander and may not be indicative of general practice.

In contrast to the Roman and, to a lesser degree, the Classical Greek armies about whose weapons and tactical training comprehensive accounts survive, Seleucid training practice, as well as that of other Hellenistic armies, is entirely obscure. Passing over various references to the pre-military functions of the gymnasiums, which ought not to be overestimated, all the information we have is that weapon and warfare instructors served in the military training school at Apamea (Strabo 16.2.10(752)). In view of the presumable organization of the Guard, it may be concluded that new recruits to the Guard, i.e. the sons of the military settlers, received their initial training there, which means in effect that all military settlers were trained at Apamea at one time or another. I do not imagine that there was a similar military school in the eastern part of the Empire, despite the administrative division of the Seleucid realm into two separate parts and despite the enormous distances recruits from Media had to cover on the way to Apamea.