The Commonwealth of Australia is a federative constitutional monarchy under a parliamentary democracy. The Commonwealth of Australia was formed in 1901 as a result of an agreement between six self-governing British colonies, which became the six States. The terms of this agreement 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 structure of the Australian Government may be examined in light of two distinct concepts, namely federalism and the separation of powers into legislative, executive and judiciary branches of government. Separation of powers is implied from the structure of the Constitution which breaks down the branches of government into separate chapters.