The Prime Minister is the head of government in Sweden. Before the creation of the office of a Prime Minister in 1876, Sweden did not have a head of government separate from its head of state, namely the King, in whom the executive authority was vested. Louis Gerhard De Geer, the architect behind the new bicameral Riksdag of 1866 that replaced the centuries old Riksdag of the Estates, became the first officeholder in 1876.