On 1 March 1901 the six former self-governing colonies transferred their exiting naval and military forces to the Federal Government. This is the date recognised as the ‘birth’ of the Australian Navy. Ten years later, the Australian Navy received the ‘Royal’ prefix, recognising it as an integral, yet distinct, part of the British Empire’s Imperial Fleet.

For the next five decades the RAN (and other Commonwealth navies) proudly wore the Royal Navy’s White Ensign in peace and war, but as Australian foreign and security policy became more independent this grew increasingly inappropriate. The RAN recognised that it needed a unique ensign to indicate that it was an independent Service of an independent nation. The new Australian White Ensign received Royal assent on 22 December 1966. It mirrored the design of the Australian National Flag with the background colour reversed to white and the stars rendered in blue. The distinctive naval design was formally introduced on 1 March 1967.