The Thirty

The Thirty were a pro-Spartan oligarchy installed in Athens after its defeat in the Peloponnesian War in 404 B.C.

The Thirty maintained power for eight months. Although brief, their reign resulted in the killing of around five percent of the Athenian population, the confiscation of citizens' property, and the exile of other democratic supporters. [Wolpert, Andrew, Remembering Defeat: Civil War and Civic Memory in Ancient Athens (2002)]

They became known as the "Thirty Tyrants" because of their cruel and oppressive tactics.