Demosthenes (, died 413 BC), son of Alcisthenes, was an Athenian general during the Peloponnesian War. Early military actions The military activities of Demosthenes are first recorded from 426 BC when he led an Athenian invasion of Aetolia. This was a failure. Demosthenes lost about 120 Athenians along with his second-in-command, Procles. Demosthenes' allies also suffered heavy losses. As a result of this loss, Demosthenes did not return to Athens, fearing for his life. However, later that year, Ambracia invaded Acarnania. The Acarnanians sought help from Demosthenes, who was now patrolling the coast of the Ionian Sea with twenty Athenian ships. He landed at Olpae and defeated a Spartan army under Eurylochus, which had come to assist the Ambraciots. Eurylochus was killed in the Battle of Olpae and the Acarnanians and Ambraciots signed a peace treaty. Success in the Peloponnese In 425 BC, while still with his fleet in the Ionian Sea, he was ordered by Cleon to join a fleet sent from Athens to put down a revolt in Sicily. Due to a storm, Demosthenes instead landed at Pylos in the Peloponnese. In order to keep his soldiers busy, he had them fortify the port, giving Athens a strong base close to Sparta. Sparta, meanwhile, landed an army on the nearby island of Sphacteria, and Demosthenes moved his men to the beach to prevent the Spartans, commanded by Thrasymelidas and Brasidas, from landing there. The Spartan landing was repulsed, and the main Athenian fleet (having turned back from its journey to Sicily) arrived in time to chase off the Spartan ships. Back in Athens, the Spartans tried to negotiate a peace. This failed, and Cleon went to assist Demosthenes, who was planning an invasion of Sphacteria. The Athenian forces successfully attacked Sphacteria, forcing the Spartans to surrender – a very unusual event. See Battle of Pylos and Battle of Sphacteria. Further action during the Peloponnesian War In 424 BC, Demosthenes and Hippocrates attempted to capture Megara, but were defeated by Brasidas. Demosthenes then went to Naupactus to support the democratic revolution there and to gather troops for an invasion of Boeotia. Demosthenes and Hippocrates were unable to coordinate their attacks and Hippocrates was defeated at the Battle of Delium. Demosthenes instead attacked Sicyon and was defeated as well. Demosthenes was one of the signatories of the Peace of Nicias in 421 BC, which ended the first half of the