The Australian Constitution is contained in an Act of the British Parliament. This is because the British Parliament was the only body in 1900 which could make laws for the whole of Australia; the parliaments of the various colonies, as they then were, made laws only for their particular colonies. A law made by the British Parliament was the only legal way to establish a system of government for the whole of Australia. The act is entitled:

COMMONWEALTH OF AUSTRALIA CONSTITUTION ACT

An Act to constitute the Commonwealth of Australia

[9th July 1900]

Whereas the people of New South Wales, Victoria, South Australia, Queensland, and Tasmania, humbly relying on the blessing of Almighty God, have agreed to unite in one indissoluble Federal Commonwealth under the Crown of the United Kingdom of Great Britain and Ireland, and under the Constitution hereby established:

And whereas it is expedient to provide for the admission into the Commonwealth of other Australasian Colonies and possessions of the Queen:

Be it therefore enacted by the Queen’s most Excellent Majesty, by and with the advice and consent of the Lords Spiritual and Temporal, and Commons, in this present Parliament assembled, and by the authority of the same, as follows:-