Lysander was the Spartan admiral who defeated Athens at the Battle of Aegospotami in 405 BCE.
The battle took place in the Hellespont during the final phase of the Peloponnesian War. Lysander captured most of the Athenian fleet while it was drawn up on shore, reportedly after observing its routine for several days. The loss was catastrophic because Athens depended on its fleet for food shipments and communications.
After Aegospotami, Lysander sailed toward Athens and helped force its surrender in 404 BCE. Sparta then imposed terms including the destruction of Athens’ Long Walls and a reduction of its naval power.
Lysander is sometimes confused with Brasidas, another prominent Spartan commander of the war. Brasidas fought mainly on land and died at Amphipolis in 422 BCE, whereas Lysander’s decisive achievement was the destruction of Athenian sea power.