The struggle among the Diadochi reached its climax when Antigonus, after the extinction of the old royal line of Macedonia, proclaimed himself king the details of the conflict, and if there was in fact a
pitched battle, are unknown, and Jansani warns that "there are very little details about the battle or skirmish they fought, and that none of the ancient authors depicted either Seleucus or Chandragupta as the clear victor of this battle. This lack of information about the encounter and the ensuing treaty means that it is impossible to reconstruct them." Wheatley and Heckel suggest that the degree of friendly Maurya-Seleucid relations established after the war implies that the hostilities were probably "neither prolonged nor grievous". The two leaders ultimately reached an agreement, and through a treaty sealed in 303 BC, Seleucus abandoned the territories he could never securely hold in exchange for stabilizing the East and obtaining elephants, with which he could turn his attention against his great western rival, Antigonus Monophthalmus. The 500 war elephants Seleucus obtained from Chandragupta were to play a key role in the forthcoming battles, particularly at Ipsus against Antigonus and Demetrius. The Maurya king might have married the daughter of Seleucus. According to Strabo, the ceded territories bordered the Indus: The geographical position of the tribes is as follows: along the Indus are the Paropamisadae, above whom lies the Paropamisus mountain: then, towards the south, the Arachoti: then next, towards the south, the Gedroseni, with the other tribes that occupy the seaboard; and the Indus lies, latitudinally, alongside all these places; and of these places, in part, some that lie along the Indus are held by Indians, although they formerly belonged to the Persians. Alexander [III 'the Great' of Macedon] took these away from the Arians and established settlements of his own, but
Seleucus Nicator gave them to
Sandrocottus [Chandragupta], upon terms of intermarriage and of receiving in exchange five hundred elephants. — Strabo 15.2.9 From this, it seems that Seleucus surrendered the easternmost parts of the provinces of
Arachosia,
Gedrosia,
Paropamisadae and perhaps also
Aria. On the other hand, he was accepted by other satraps of the eastern provinces. His Persian wife, Apama, may have helped him implement his rule in
Bactria and
Sogdiana. This would tend to be corroborated archaeologically, as concrete indications of Mauryan influence, such as the inscriptions of the
Edicts of Ashoka which are known to be located in, for example,
Kandhahar in today's southern Afghanistan. ruler, with royal diadem. Temple of the Oxus,
Takht-i Sangin, 3rd–2nd century BC,
Tajikistan.Some authors say that the argument relating to Seleucus handing over more of what is now southern Afghanistan is an exaggeration originating in a statement by Pliny the Elder referring not specifically to the lands received by Chandragupta, but rather to the various opinions of geographers regarding the definition of the word "India": Most geographers, in fact, do not look upon India as bounded by the river Indus, but add to it the four satrapies of the
Gedrose, the
Arachotë, the
Aria, and the
Paropamisadë, the
River Cophes thus forming the extreme boundary of India. According to other writers, however, all these territories, are reckoned as belonging to the country of the Aria. — Pliny, Natural History VI, 23 The span of control of the Mauryas is also questioned by present-day archaeologists, and the idea that the ceded territory included all of Aria and Gedrosia (Balochistan) seems unlikely. The alliance between Chandragupta and Seleucus was affirmed with a marriage (
Epigamia). Chandragupta or his son may have married a daughter of Seleucus, or perhaps there was diplomatic recognition of intermarriage between Indians and Greeks. An Indian
Puranic source, the
Pratisarga Parva of the
Bhavishya Purana, described the marriage of
Chandragupta with a Greek ("
Yavana") princess, daughter of Seleucus (
Suluva in Indian sources). In addition to this matrimonial recognition or alliance, Seleucus dispatched an ambassador,
Megasthenes, to the Mauryan court at
Pataliputra (Modern
Patna in
Bihar state). Only short extracts remain of Megasthenes' description of the journey. The other parts of the country beyond the
Hydaspes, the farthest extent of Alexander's conquests were discovered and surveyed by Seleucus Nicator: namely • from thence (the
Hydaspes) to the
Hesudrus 168 miles • to the river
Ioames (
Yamuna) as much: and some copies add 5 miles more therto • from thence to
Ganges 112 miles • to
Rhodapha 119, and some say, that between them two it is no less than 325 miles. • From it to
Calinipaxa, a great town 167 miles-and-a-half, others say 265. • And to the confluent of the rivers
Iomanes and Ganges, where both meet together, 225 miles, and many put thereto 13 miles more • from thence to the town
Palibotta 425 miles • and so to the mouth of the Ganges where he falleth into the sea 638 miles. — Pliny the Elder, Natural history, Book 6, Chap 21 Seleucus apparently minted coins during his stay in India, as several coins in his name are in the Indian standard and have been excavated in India. These coins describe him as "Basileus" ("King"), which implies a date later than 306 BC. Some of them also mention Seleucus in association with his son Antiochus as king, which would also imply a date as late as 293 BC. No Seleucid coins were struck in India thereafter and confirm the reversal of territory west of the Indus to Chandragupta. Seleucus may have founded a navy in the
Persian Gulf and in the Indian Ocean.
Battle of Ipsus of Seleucus I, minted at
Susa.
Obv: Portrait of male figure (probably Seleucus, but possibly Alexander or Dionysus), The war elephants Seleucus received from Chandragupta proved to be useful when the Diadochi finally decided to deal with Antigonus. Cassander, Seleucus and Lysimachus defeated Antigonus and Demetrius in the
battle of Ipsus. Antigonus fell in battle, but Demetrius escaped. After the battle, Syria was placed under Seleucus' rule. He understood Syria to encompass the region from the
Taurus Mountains to
Sinai, but Ptolemy had already conquered
Palestine and
Phoenicia. In 299 BC, Seleucus allied with Demetrius and married his daughter
Stratonice. Stratonice was also the daughter of Antipater's daughter
Phila. Seleucus had a daughter by Stratonice, who was also called
Phila. The fleet of Demetrius destroyed Ptolemy's fleet and thus Seleucus did not need to fight him. Seleucus, however, did not manage to enlarge his kingdom to the west. The main reason was that he did not have enough Greek troops. During the battle of Ipsus, he had less infantry than Lysimachus. His strength was in his war elephants and in traditional Persian cavalry. In order to enlarge his army, Seleucus tried to attract colonists from mainland Greece by founding four new cities—
Seleucia Pieria and
Laodicea in Syria on the coast and
Antioch on the Orontes and
Apameia in the
Orontes River valley.
Antioch became his chief seat of government. The new Seleucia was supposed to become his new naval base and a gateway to the Mediterranean. Seleucus also founded six smaller cities.
Defeat of Demetrius and Lysimachus Seleucus nominated his son
Antiochus I as his co-ruler and viceroy of the eastern provinces in 292 BC, the vast extent of the empire seeming to require a double government. Seleucus was thus able to get Stratonice out of the way, as her father Demetrius had now become king of Macedonia. The alliance between Seleucus and Demetrius ended in 294 BC when Seleucus conquered
Cilicia. Demetrius invaded and easily conquered Cilicia in 286 BC, which meant that Demetrius was now threatening the most important regions of Seleucus' empire in Syria. Demetrius' troops, however, were tired and had not received their payment. Seleucus, on the other hand, was known as a cunning and rich leader who had earned the adoration of his soldiers. Seleucus blocked the roads leading south from Cilicia and urged Demetrius' troops to join his side. Simultaneously he tried to evade battle with Demetrius. Finally, Seleucus addressed Demetrius personally. He showed himself in front of the soldiers and removed his helmet, revealing his identity. Demetrius' troops now started to abandon their leader
en masse. Demetrius was finally imprisoned in Apameia and died a few years later in captivity. Lysimachus and Ptolemy had supported Seleucus against Demetrius, but after the latter's defeat the alliance started to break apart. Lysimachus ruled Macedonia,
Thracia and
Asia Minor. He also had problems with his family. Lysimachus executed his son
Agathocles, whose wife
Lysandra escaped to Babylon to Seleucus. The unpopularity of Lysimachus after the murder of
Agathocles gave Seleucus an opportunity to remove his last rival. His intervention in the west was solicited by
Ptolemy Keraunos, who, on the accession to the Egyptian throne of his brother
Ptolemy II (285 BC), had at first taken refuge with Lysimachus and then with Seleucus. Seleucus then invaded Asia Minor and defeated his rival in the
Battle of Corupedium in
Lydia, 281 BC. Lysimachus fell in battle. In addition, Ptolemy had died a few years earlier. Seleucus was thus now the only living contemporary of Alexander.
Administration of Asia Minor Before his death, Seleucus tried to deal with the administration of Asia Minor. The region was ethnically diverse, consisting of Greek cities, a Persian aristocracy and indigenous peoples. Seleucus perhaps tried to defeat
Cappadocia, but failed. Lysimachus' old officer
Philetairos ruled
Pergamon independently. On the other hand, based on their names, Seleucus apparently founded a number of new cities in Asia Minor. Few of the letters Seleucus sent to different cities and temples still exist. All cities in Asia Minor sent embassies to their new ruler. It is reported that Seleucus complained about the number of letters he received and was forced to read. He was apparently a popular ruler. In
Lemnos he was celebrated as a liberator and a temple was built to honour him. According to a local custom, Seleucus was always offered an extra cup of wine during dinner time. His title during this period was Seleucus
Soter ("saviour"). When Seleucus left for Europe, the organizational rearrangement of Asia Minor had not been completed. ==Death and legacy==