Seleucus Returns to Babylon
Background In about 320 BC, Seleucus had become the Governor of Babylon, however by 315 BC he was forced to flee the city when Antigonus Monophthalmos invaded.
Seleucus fled to Egypt. It was at this time that the remaining Diadochi kings (Cassander in Macedonia, Lysimachus in Thrace, and Ptolemy I in Egypt) formed an alliance and waged war against Antigonus. Seleucus served as an admiral in the navy of Ptolemy I and proved himself to be very capable. Meanwhile on land, Ptolemy’s forces defeated those of Antigonus at the battle of Gaza, allowing Ptolemy to advance up the coast of the Levant.
The March to Babylon
At this time, Ptolemy gave Seleucus a tiny force of 800 infantry and 200 cavalry so that he could return to Babylon. Seleucus was able to raise an additional 3,000 men from the towns and Greek colonies along the route and quickly retook Babylon. Nevertheless, his force was far too small to hold the city in the traditional way, when Antigonus’s allies (the satraps of Media and Aria) arrived to retake Babylon, Seleucus had hid his forces in the swamps around the city and launched a surprise attack during the night. Evangorus, the Satrap of Aria was killed and in the ensuing confusion, a great number of his men surrendered and agreed to fight for Seleucus.
Seleucus now had about 20,000 men, but was still not powerful enough to face Antigonus in open battle. Instead Seleucus went east and seized control of the eastern provinces of the Empire.