The Great Council of Venice or Major Council (Italian: Maggior Consiglio; Venetian: Mazor Consegio), originally the Consilium Sapientis (Latin for "Council of Wise Men"), was a political organ of the Republic of Venice between 1172 and 1797 and met in a special large hall of the Palazzo Ducale. Participation in the Great Council was established on hereditary right, exclusive to the patrician families enrolled in the Golden Book of the Venetian nobility. The Great Council was also unique at the time in its usage of lottery to select nominators for proposal of candidates, who were thereafter voted upon. The Great Council had the power to create laws and elected the Council of Ten.
In 1143 the Consilium Sapientis was formally established as a permanent representation of the sovereign Concio (or assembly) of freemen (citizens and patricians). The Act formalized the set-up in communal form of the State, with the birth of the Commune Veneciarum ("City of Venice"). Thirty years later (1172) the Consilium was transformed into sovereign assembly known as the Great Council. The council initially consisted of 35 councilors, but gradually expanded to over 100. Some members were added to the Council of the Forty, which served effectively as a Supreme Court or highest of constitutional bodies. The Forty was established around 1179.
Proposals for participation in the transformation of the hereditary right to counsel or co-opted by the board itself had already been presented and rejected several times under dogadi of Giovanni Dandolo, in 1286.
However, under Doge Pietro Gradenigo the nobility insisted that to ensure more stability and continuity of participation in the Government of the Republic, new laws needed to be enacted. This was brought together on 28 February 1297, an event known as the Serrata (Lock-out). This provision of law opened the Great Council only to those who already had been part of the preceding four years, and every year, forty raffled among their descendants. The reform also removed time limits on how long a person could be a member of the Council.