- Seleucus I Nicator ("the Victor") (satrap, 321–305 BC; king, 305–281 BC) was the founder of the Seleucid Empire. He had served as an infantry commander under Alexander the Great and became chiliarch (i.e. vizier) to Perdiccas at the Settlement of Babylon (323 BC). In 321 BC, after the death of Perdiccas he was appointed satrap (governor) of Babylonia. He was driven out by Antigonus Monophthalmus in 315 BC, but managed to return and hold the satrapy in 312. Seleucus I assumed the royal title in 305 BC and embarked upon a great eastern campaign that created a Seleucid Empire stretching from Babylonia and Syria to the borders of India. He played a pivotal role in the defeat and death of Antigonus at the Battle of Ipsus (301 BC). Seleucus I expanded his empire into Asia Minor after defeating and killing Lysimachus, the king of Thrace who had claimed Antigonus' territories in Asia Minor, at the Battle of Corupedium (281 BC). Seleucus I was assassinated later in 281 BC as he advanced to take possession of Thrace.