The National Colonial Flag for Australia (1823/24) was the forerunner of the many Australian flag designs which featured the Southern Cross

Crux

Crux is the smallest of the 88 modern constellations, but is one of the most distinctive. Its name is Latin for cross, and it is dominated by a cross-shaped asterism that is commonly known as the Southern Cross.-Visibility:...

 and Union Flag

Union Flag

The Union Flag, also known as the Union Jack, is the flag of the United Kingdom. It retains an official or semi-official status in some Commonwealth Realms; for example, it is known as the Royal Union Flag in Canada. It is also used as an official flag in some of the smaller British overseas...

 in combination. It is the first recorded attempt to design a distinctive national flag for Australia. Designed by Captain John Bingle and Captain John Nicholson

John Nicholson

-In politics:*John Nicholson , United States Representative from New York*John A. Nicholson , United States Representative from Delaware*John Robert Nicholson , Canadian former Lieutenant-Governor of British Columbia...

, both New South Wales

New South Wales

New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...

 residents, it is inspired by the White Ensign

British ensigns

This article concerns the ensigns flown by vessels and aircraft of the United Kingdom and its overseas territories, and by certain nations of the Commonwealth....

 of the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

, the protector and defender of Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 from 1788 to 1913. The large red cross of St George

St George's Cross

St George's Cross is a red cross on a white background used as a symbolic reference to Saint George. The red cross on white was associated with St George from medieval times....

features four white, eight pointed stars representing the Australian Southern Cross. According to Captain Bingle it was adopted by the Government of Sir Thomas Brisbane. The National Colonial Flag was the first flag designed specifically to represent Australia.
Illustrated Retrospect of Present Century - John Bingle (1881)

"Many years ago as far back as 1823 or 1824 I assisted Captain Nicholson RN, the first Harbour Master of Port Jackson, to plan and recommend to the Lords of the Admiralty a National Colonial Flag for Australia which met with their Lordships approval and adopted by the Government of Sir Thomas Brisbane. Our proposition had the British National St George's Ensign adding Four (4) Stars placed in the four quarters of the Cross in the fly of the Ensign as the emblem of our Hemisphere THE GREAT SOUTHERN CROSS. The flag has lately been disfigured by adding another star in the centre of the Cross by some one not comprehending the original intention and embodying American notions. Sydney in those days was Australia ! and no other province to represent so that adding more Stars frustrated the original intention."