http://agathe.gr/democracy/the_boule.html
The Boule (The Senate) The Athenian legislature also included a deliberative body known as the Boule. It was made up of 500 members -- 50 from each of the 10 tribes -- who were chosen by lot and served ... Despite the religious aspects of the building, violence and sacrilege occurred occasionally during troubled political times, as in 404/3 B.C.: Theramenes leaped to Hestia Boulaia ...