The Government of Australia is the government of the Commonwealth of Australia, a federal parliamentary constitutional monarchy. It is also commonly referred to as the Australian Government, the Commonwealth Government, or the Federal Government.
The Commonwealth of Australia was formed in 1901 as a result of an agreement among six self-governing British colonies, which became the six states. The terms of this contract are embodied in the Australian Constitution, which was drawn up at a Constitutional Convention and ratified by the people of the colonies at referendums. The Australian head of state is the Queen of Australia who is represented by the Governor-General of Australia, with executive powers delegated by constitutional convention to the Australian head of government, the Prime Minister of Australia.
The Government of the Commonwealth of Australia is divided into three branches: the executive branch, composed of the Federal Executive Council, presided by the Governor-General, which delegates powers to the Cabinet of Australia, led by the Prime Minister; the legislative branch, composed of the Parliament of Australia's House of Representatives and Senate; and the judicial branch, composed of the High Court of Australia and the federal courts. Separation of powers is implied by the structure of the Constitution, the three branches of government being set out in separate chapters (chapters I to III). The Australian system of government combines elements of the Westminster and Washington systems with unique Australian characteristics, and has been characterised as a "Washminster mutation".