The Aussie slouch hat and rising sun badge
Nola Watt

The Australian Army’s slouch hat, made famous by several generations of Diggers, has become a symbol, readily recognized by the wide – brimmed khaki felt hat with the left side cocked up and displaying the rising sun badge.

Pioneering squatters adopted wide-brimmed felt hats for protection from the harsh sun and several of Australia’s colonial armies wore them for the same reason – the New South Wales Lancers, New South Wales Rifles and the Victorian Mounted Rifles.  Usually the brim was turned down all around.  During the Boer War this type of hat became almost universal headgear for British and Empire troops in South Africa – the reason being a critical shortage of cork helmets.  However, when supply of the helmets arrived, Colonel Tom Price’s Victorian contingent rebelled.  They organized a mass raid on the British Yeomanry Regiment’s ‘bush hats’ and wore them and then ‘they were slouch hatted to a man!’

In 1903, after Federation, the slouch hat became standard headdress in the reorganized Australian Army.  It appeared with the left side clipped-up to enable the rifle to be carried at the slope.

In WWI It was also worn by the Australian Flying Corps.  Since WWII the slouch hat came to the fore as the symbol of the Australian Soldier and has been in service since then.

Reference: 
Australian Defence Heritage
Frank Doak 1988 Published Fairfax Library
Broadway, NSW