Antigonid forces under Antigonus's oldest son, Demetrius, besieged the Seleucid garrison of the city of Babylon under the command of Patrocles.
Seleucus had left a small force in the city under the command of an admiral and geographer called Patrocles.
The defenders launched guerrilla attacks at the young Antigonid's troops, and Patrocles also managed to hold off Demetrius by using the irrigation canals to flood the area.
[2] Before Demetrius arrived, Patrocles ordered an evacuation of civilians from the city, then he withdrew with his troops into Babylon’s two citadels.
In 309 BC Demetrius marched back west with the majority of his army, but left Archelaus, one of his trusted generals, with 6,000 troops and orders to take the remaining citadel.