Pyrrhus (pĭrˈəs) [key], c.318–272 B.C., Molossian king of Epirus. He fought at Ipsus in Asia Minor in the service of Demetrius Poliorcetes (later Demetrius I) of Macedon, and by the aid of Ptolemy I he became (297 B.C.) joint king of Epirus with Neoptolemus. He removed (295) Neoptolemus from the throne, but before his kingdom was consolidated he went to war with Demetrius (291–286); Pyrrhus obtained half of Macedonia and Thessaly but was driven back (c.286) by Lysimachus. He then went to S Italy with a large force to aid the Tarentines and defeated (280) the Romans at Heraclea. In the same year Pyrrhus' peace proposals were rejected by the Romans. In 279 he again defeated the Romans at Asculum in Apulia. His heavy losses caused him to declare, "one more such victory and I am lost," thus the origin of the term "Pyrrhic victory." At Beneventum (now Benevento) he was barely defeated (275) by the Romans. He again attempted to conquer Macedonia, defeating (273) Antigonus II. Turning his attention suddenly to the Peloponnesus, he failed to take Sparta by siege. He then fled to Argos, where he was killed by a mob in the street. He accomplished nothing beyond bringing Epirus to ruin.