Seleucus being now master of the city and castle, judged it necessary to raise what forces he could, not doubting that Antigonus would soon send an army to drive him from these acquisitions. Accordingly, while he was busy in recruiting his army and disciplining his new-raised troops, news was brought him that Nicanor, governor of Media under Antigonus, was advancing against him, at the head of ten thousand foot, and seven thousand horse. Upon this intelligence Seleucus marched out to meet him with three thousand foot and four hundred horse only, and passing the Tigris, concealed his men, as the enemy drew near, in the fens hard by the river, with a design to attack Nicanor unexpectedly; who not having had any intelligence of Seleucus’ march, encamped in a disadvantageous post, where he was the following night surprised, and his army, after great slaughter, put to the rout. Such of the soldiers as survived the slaughter declared for Seleucus—a circumstance which enabled him to pursue his conquests, and reduce in a short time all Media and Susiana, with many of the adjacent provinces. Having, by this victory, established his interest and power in Babylon, he daily improved them by the clemency of his government, and by his justice, equity, and humanity, to such a degree that, from so low a beginning, he became, in a few years, the greatest and most powerful of all Alexander’s successors.
And now Seleucus, seeing himself in quiet possession of Babylon and its territory, advanced at the head of a considerable army into Media, where he engaged and slew with his own hand Nicanor, or, as others call him, Nicator, whom Antigonus had sent against him. Having reduced all Media, he pursued his march into Persia, Bactria, Hyrcania, etc., subjecting to his new empire these and all the other provinces on this side the Indus, which had been formerly conquered by Alexander. In the meantime Antigonus and Demetrius having assumed the title of king, Seleucus imitated their example, styling himself king of Babylon and Media.
Having therefore no enemy to fear on this side the Indus, he resolved to cross that river, and, by a sudden irruption, make himself master of those vast provinces which were known by the name of India. These Alexander had formerly subdued; but after his death, while his successors were engaged in mutual wars with each other, one Sandrocottus, or, as others call him, Androcottus, an Indian of mean extraction, under the specious pretence of delivering his country from the tyranny of foreigners, had raised a powerful army, and having driven out the Macedonians, seized the Indian provinces for himself. To recover these provinces Seleucus crossed the Indus: but finding that Sandrocottus had made himself absolute master of all India and drawn into the field an army of six hundred thousand men, with a prodigious number of elephants, he did not judge it advisable to provoke so great a power; and therefore entering into a treaty with him, he agreed to renounce all his pretensions to that country, provided Sandrocottus furnished him with five hundred elephants—which proposal the Indian prince willingly agreeing to, a peace was concluded between them.
Seleucus marching into the upper Syria, made himself master of that rich province, and built on the river Orontes the city of Antioch, which soon became, and continued to be for many ages, the metropolis of the East; for the Syrian kings, and afterwards the Roman governors, who presided over the affairs of the eastern provinces, chose it for their place of residence; and afterward in the Christian times, it was the see of the chief patriarch of Asia. Besides Antioch, Seleucus built in the same country several other cities of less importance.
[283-273 B.C.]
A few months after the decease of Demetrius, died also Ptolemy Soter, king of Egypt, so that two only of Alexander’s captains survived,—viz., Lysimachus and Seleucus. As they were each upwards of seventy, it was expected that they should have closed the scene of life in the union which had subsisted so long between them, for they had ever been closely united, and, to the utmost of their power, supported each other; but it happened quite otherwise; a war, which proved fatal to both, soon breaking out between them.
Seleucus was easily persuaded to engage in this war, being already sufficiently inclined to it on other accounts; but before he embarked in so great an undertaking, he not only resigned to his son Antiochus a considerable part of his empire, but also, by an unparalleled example, his favourite queen Stratonice. Seleucus having, without much difficulty, prevailed upon Stratonice to accept of a young prince for her husband instead of an old king, the nuptials were solemnised with the utmost pomp and magnificence; after which Antiochus and Stratonice were crowned king and queen of upper Asia, Seleucus willingly resigning to them all those provinces.