The peace did not last, however. In 418 BC allied forces of Athens and Argos were defeated by Sparta at Mantinea. In 415 Athens launched an ambitious naval expedition to dominate Sicily; the expedition ended in disaster at the harbor of Syracuse, with almost the entire army killed and the ships destroyed. Soon after the Athenian defeat in Syracuse, Athens' Ionian allies began to rebel against the Delian league, while Persia began to once again involve itself in Greek affairs on the Spartan side. Initially the Athenian position continued relatively strong, with important victories at Cyzicus in 410 and Arginusae in 406. However, in 405 the Spartan Lysander defeated Athens in the Battle of Aegospotami, and began to blockade Athens' harbour; driven by hunger, Athens sued for peace, agreeing to surrender their fleet and join the Spartan-led Peloponnesian League.