After Athens' defeat in the Peloponnesian War, Thrasybulus led the democratic resistance to the new oligarchic government, known as the Thirty Tyrants, imposed by the victorious Spartans upon Athens. In 404 BC, he commanded a small force of exiles that invaded the Spartan-ruled Attica and, in successive battles, defeated first a Spartan garrison and then the forces of the oligarchy. In the wake of these victories, democracy was re-established at Athens. As a leader of this revived democracy in the 4th century BC, Thrasybulus advocated a policy of resistance to Sparta and sought to restore Athens' imperial power. He was killed in 388 BC while leading an Athenian naval force during the Corinthian War.