The second factor was the political reforms of Clisthenes in 508 B.C. After the fall of the tyrants, Isagoras, a noble, tried to reverse the rising independence of the lower classes. This effort was blocked in 508 by Clisthenes, a member of the Alcmeonid family, who assumed the leadership position. Clisthenes intended to permanently break the power of local social units in favor of the state, and to make sure power was permanently placed in the hands of the people. He organized the populace into demes or political units numbering about 170. Clisthenes required that each tribe contain demes located in the country, the city, and the coast so that self-interest was equally distributed.
He also established a council of 500, consisting of 50 men from each tribe. The 500 were chosen by lot to make sure the elected asemblymen were independent. The council had responsibility for preparing bills for the assembly and supervising public business.