Seleucus I Nicator ("Conqueror") (died 280 B.C.E.): One of the Diadochi, or successors of Alexander the Great. A personal friend of Alexander, he had initially had no part in the division of power after Alexander's death -- but a victory at Gaza in 312 allowed him to establish himself in Babylon and the east. He founded what came to be known as the "Seleucid Emperor," the largest of the successor states. He was generally considered the most enlightened of the monarchs and, after his victory at Corupedium in 281, he seemed poised to reunite most of Alexander's Empire. But he was promptly assassinated by Ptolemy Ceraunos. His son Antiochus I managed to hold together a smaller Seleucid Emperor, but the hope for a reunited Macedonian monarchy was gone.