Flag Adopted: 12 April 1606 (in the United Kingdom)
Flag Proportion: 3:5
Use: State Flag
Captain James Cook flew the first ever flag as we know it on Australian soil when he took possession of the east coast of Australia (in the name of King George III) at Botany Bay on 29 April 1770. The flag flown was, of course, the Union Flag of Great Britain.
However, the Union Flag didn′t officially fly on Australian soil until Governor Arthur Phillip took formal possession of the Australian continent (to 135° E) under the construct of "terra nullius" and named it the Colony of New South Wales on 26 January 1788.
The Union Flag dates from 1606, adopted after England and Scotland formed a United Kingdom under King James I (VI of Scotland) in 1603. The Union Flag combined the red cross of Saint George (England) with the white-on-blue saltire of Saint Andrew (Scotland) - the national flags of these two countries.
Eric Inglefield, Kingfisher, John Wiley and Sons, Canada, 1979.
Flags and Arms Across the World
Dr Whitney Smith, McGraw-Hill, New York, 1980.
A Short History of Australia
Manning Clark, 4th Revised Edition, Penguin, Melbourne, 1995.
What Happened When
Anthony Barker, Allen and Unwin, Sydney, 1992.