Theramenes, who had been to Sparta as part of the negotiation team to end the war, opposed this step as unlawful and immoral. He demanded that The Thirty allow more participation in the Athenian government so they responded by drawing up a list of three thousand who would participate in the government. All other Athenians were disarmed and excluded from the system. Now The Thirty began their reign of terror against the rich and all who opposed them.
Kritias, the unofficial leader of the group, was again opposed by Theramenes, who was denounced and forced to take poison. This caused a general revolt that saw a rebel group located in Peiraieus defeat the army of The Thirty killing Kritias and Hippomachos. The remainder of The Thirty retreated to Eleusis and begged for Spartan help.