THRASYBULUS, an Athenian general, whose public career began in 411 B.C., when by his resolute behaviour he frustrated the oligarchic rising in Samos (see Peloponnesian War), and secured the Athenian armament to the cause of democracy. Elected general by the troops, he effected the recall of Alcibiades and assisted him in the ensuing naval campaigns. By his brave defence at Cynossema (411) he won the battle for Athens, and in 410 contributed towards the brilliant victory of Cyzicus. In 406 he fought at Arginusae as a simple ship's captain, but after the engagement was commissioned with Theramenes (q.v.) to rescue some drowning crews. In the subsequent inquiry Thrasybulus successfully disclaimed responsibility for the failure.
In 404, when exiled by the Thirty Tyrants for his services to the democracy, he retired to Thebes and there prepared for a desperate attempt to recover his country. Late in the year, with seventy men, he seized Phyle, a hill fort on Mt Parnes. A force sent by the Thirty was repulsed and routed by a surprise attack. Thrasybulus now gained the Peiraeus, 1000 strong, and successfully held the steep hill of Munychia against the oligarchs' full force. After this repulse the Thirty gave way to a provisional government of moderate oligarchs. Meanwhile a Spartan fleet, which the latter had summoned, blockaded the Peiraeus, but king Pausanias, commanding the land forces, after some skirmishes effected a general reconciliation by which the democracy was restored (October 403). Thrasybulus was now the hero of the people; but a decree by which he secured the franchise for all his followers, including many slaves, was rescinded as illegal.
In 395 Thrasybulus induced Athens to join the Theban league against Sparta, but did not himself take the field till 389, when he led a new fleet of 40 ships against the Spartans at Rhodes. Sailing first to the Bosporus he effected a democratic revolution at Byzantium and renewed the corn-toll. After a successful descent on Lesbos and the renewal of the 5% import tax at Thasos and Clazomenae he sailed south in quest of further contributions, but met his death in a night surprise by the people of Aspendus. By his exactions he had forfeited the confidence both of the allies and of Athens; but after his death the ill-feeling subsided, and he was ever remembered as one of the saviours of his country.
See Thucydides, viii. 75-105; Xenophon, Hellenica; Lysias. c. Eratosth. 55-61 and c. Ergocl. 5, 8; and Const, ath. xl. Diodorus xiii., xiv., Justin v. 9, 10, and Nepos depend almost wholly on Xenophon. Corpus inscr. att. ii. 11b and 14b.