Born circa 358 B.C.; died 281 or 280 B.C. Founder of the Seleucid dynasty and state.
Seleucus I Nicator gained prominence as a general of Alexander the Great. In 321, soon after Alexander’s death, he assumed command of the satrapy of Babylonia, where, in 312, he entrenched himself in power (312 B.C is the starting point of the Seleucid calendar). Contending for power with the other Diadochoi, he annexed Media, Susiana, Persis, and Bactria. In 305 he declared himself king.
Seleucus I Nicator made a successful campaign into India, but when he received troubling news from the west, he made peace with the Indian king Chandragupta, ceding lands west of the Indus River in exchange for 500 elephants. After the battle of Ipsus (301), when the Diadochoi formally partitioned the empire of Alexander, Seleucus received Mesopotamia and Syria. In 281 he defeated Lysimachus near Corupedium and subsequently occupied almost all of Asia Minor. Set on conquering Thrace and Macedonia, Seleucus crossed the Hellespont with his army, but he was killed by Ptolemy Ceraunus, who had no intention of relinquishing Macedonia.