Preliminaries
After the death of Alexander the Great on 11 June 323 BC, his empire disintegrated. Officers who were trying to save it were defeated during the First War of the Diadochi. During the Second War of the Diadochi, the power of Antigonus Monophthalmus, who had created a state of his own in Anatolia and Syria, was growing; this caused alarm among the other generals, but in the Third War of the Diadochi, Antigonus managed to keep Ptolemy I Soter of Egypt and Cassander of Macedon in check. In December 311, the warring parties concluded the Peace of the Dynasts, and recognized each other. The only ruler who was excluded, was Seleucus I Nicator. Antigonus had expelled this satrap from Babylonia in 316, but Ptolemy had given him an army, which he now used to return to his satrapy.
Read more about this topic: Babylonian War