The premier of Western Australia is the head of government of the state of Western Australia. The role of premier at a state level is similar to the role of the prime minister of Australia at a federal level. The premier leads the executive branch of the Government of Western Australia and is accountable to the Parliament of Western Australia. The premier is appointed by the governor of Western Australia. By convention, the governor appoints as premier whoever has the support of the majority of the Western Australian Legislative Assembly. In practice, this means that the premier is the leader of the political party or group of parties with a majority of seats in the Legislative Assembly (lower house). Since Western Australia achieved self-governance in 1890, there have been 31 premiers. Mark McGowan is the current premier, having been appointed to the position on 17 March 2017. History The position of premier is not mentioned in the constitution of Western Australia. From 1890 to 1917, the premier was not an official position, rather, it was the title unofficially given, but widely used to refer, to the head of the government. When Western Australia became a self-governing colony in 1890, Governor William Robinson initially indicated he would use the title prime minister to refer to the head of the government. However, after he selected John Forrest, the title premier was used for consistency with the other Australian colonies. The position was first officially mentioned when the governor appointed Henry Lefroy as premier on 28 June 1917. However, when the governor designated and declared the six executive offices of the government on 2 July 1917, the position of premier was not listed, creating an ambiguity. It was not until 3 April 1947 that the premier became one of the executive offices of the government. The most common cause for a change of premier is an election. Since the 1990s, elections have occurred roughly every four years. Before then, elections were at most three years apart, except for during World War II. A less common cause for a change of premier is the ruling party changing its leader. This can occur as a result of a resignation, death or leadership spill. In this case, the new premier is whoever the party elects as its new leader. Another cause for a change of premier is a loss of majority support in the Legislative Assembly.