Lysander

Lysander, commanding the Spartan fleet, decisively defeated the Athenian navy at Aegospotami in the Hellespont. He captured nearly the entire Athenian fleet and executed thousands of Athenian prisoners, effectively ending Athenian naval power and the Peloponnesian War.

After Aegospotami, Lysander blockaded Athens by sea and forced its surrender. He imposed harsh terms: the destruction of the Long Walls, the surrender of the fleet, and the installation of the pro-Spartan oligarchy of the Thirty Tyrants, ending the Peloponnesian War.

Lysander oversaw the establishment of the Thirty Tyrants, a pro-Spartan oligarchic regime in Athens. This government executed political opponents and confiscated property, leading to widespread terror until its overthrow in 403 BC.

Lysander established pro-Spartan oligarchic governments (decarchies) in many former Athenian subject cities across the Aegean and Asia Minor. These regimes were loyal to Sparta and Lysander personally, extending Spartan influence but also creating resentment.