Pelopidas, a Theban general, killed at the battle of Cynoscephalse, in Thessaly, in 364 (according to Grote probably in 363) B. C. He inherited great possessions from his father Hippoclus, of which he made a liberal use. In a battle his life was saved by Epaminondas at great risk; and from this began a friendship which lasted until the death of Pelopi-das. His wealth and his devotion to public affairs made Pelopidas a prominent member of the popular party, so that, upon the seizure of the Cadmea by the Spartan general Phoe-bidas in 382, he with 300 others took refuge at Athens. There he remained three years, and finally projected the enterprise which restored democracy to Thebes. With six others he entered that city at nightfall, put to death the philo-Laconian polemarchs, slew Leontiades, the leader of the Spartan party, with his own hand, and gained possession of the citadel by the garrison's capitulating. From that time until his death he was every year elected one of the Bceotarchs, and in 378-'6 he bore a conspicuous part in the war against the Lacedaemonians. In 375, while returning from an attempt to surprise Orchomenus, he fell in at Tegyra with a Spartan force superior to his in number, but in the battle which followed was completely victorious.

At Leuctra in 371 he commanded the sacred band, defeated the enemy's right wing, and decided the day. Afterward he seconded Epaminondas in persuading their colleagues in the army to march into the Spartan territory, although by so doing they would exceed their terms of office, an offence which according to law was punishable with death; yet on their return they were acquitted. In 368 Pelopidas was sent to succor the inhabitants of Thessaly, oppressed by Alexander of Pherae; he occupied Larissa, and compelled the tyrant to acknowledge his authority. Advancing into Macedonia, he composed the differences between Alexander II. and Ptolemy of Alorus, and took as hostages 30 boys, among whom was Philip of Macedon. In 367 he went as envoy to the Persian court at Susa, where he obtained a rescript that Messene and Am-phipolis should be autonomous cities, that Athens should order home all the ships in active service, and that Thebes should be deemed the head city of Greece. Shortly after his return Pelopidas was treacherously seized as a prisoner by Alexander of Pherae, while on a mission to him. Plutarch places the seizure before the time of the embassy to Persia, and Diodorus puts it at 368-'7, but several reasons are adduced by Grote for supposing it to have occurred after that embassy.

A Theban force under Epaminondas released Pelopidas. Despatched in 364 (or 363) to Thessaly at the head of an army, although the portents were unfavorable, and his troops were terrified by an eclipse of the sun, he pressed on. At Pharsalus he encountered Alexander at the head of a superior force, and a contest for the hills called Cynoscephalas immediately ensued. After a severe struggle, the tyrant was defeated; but Pelopidas, seeing Alexander himself, rushed to the spot where he was standing, attended by a few soldiers only, and was slain.