In cities of ancient Greece, the boule (Greek: βουλή, boulē; plural βουλαί, boulai) was a council of over 500 citizens (βουλευταί, bouleutai) appointed to run daily affairs of the city. Originally a council of nobles advising a king, boulai evolved according to the constitution of the city: In oligarchies boule positions might have been hereditary, while in democracies members were typically chosen by lot (→ Sortition), and served for one year. Little is known about the workings of many boulai, except in the case of Athens, for which extensive material has survived.