The Prime Minister of Canada is an official who serves as the primary minister of the Crown, chair of the Cabinet, and thus head of government of Canada. Officially, the prime minister is appointed by the Governor General of Canada, but by constitutional convention, the prime minister must have the confidence of the elected House of Commons. Normally, this is the leader of the party caucus with the greatest number of seats in the house. But, if that leader lacks support of the majority, the governor general can appoint another leader who has that support or may dissolve parliament and call a new election. By constitutional convention, a prime minister holds a seat in parliament and, since the early 20th century, this has more specifically meant the House of Commons.