The Council of Five Hundred was a key institution in ancient Athens, established by the reforms of Cleisthenes around 508-507 BCE. It served as a legislative body responsible for preparing matters to be discussed in the Assembly, which was the main decision-making body of the city. The council was composed of 500 members, with 50 representatives from each of the ten Athenian tribes. Members of the council were chosen by lot and served for one year, ensuring a rotation of citizens in governance. The council's duties included overseeing government finances, managing public works, and proposing laws. This system aimed to promote democracy and citizen participation in Athenian politics.