Alternate meaning: Lighthorse (American Indian police)
The AustralianLight Horse soldiers were mounted infantry who served during the Boer War and World War I. The Light Horse differed from cavalry in that they usually fought dismounted, using their horses as transport to the battlefield and as a means of swift disengagement when retreating or retiring. A famous exception to this rule was the charge of the 4th Light Horse Brigade at Beersheba on 31 October1917. In 1918 some light horse brigades were equipped with swords, enabling them to fight in a conventional cavalry role during the advance on Damascus.
A light horse regiment is roughly equivalent to a battalion, but containing only about 500 men (whereas an infantry battalion would contain about 1000 men). Around a quarter of this nominal strength (or one man in each section of 4) could be allotted to horse-holding duties when the regiment entered combat. A regiment was divided into three squadrons, designated "A", "B" and "C", (equivalent to a company) and a squadron divided into four troops (equivalent to a platoon). Each troop was divided into about ten 4-man sections. When dismounting for combat, one man from each section would take the reins of the other three mens' horses and lead them out of the firing line where he would remain until called upon.
The Australian waler horse was the common mount for the light horsemen.
A number of Australian light horse units are still in existence today, generally as mechanized infantry units.
The Australian Light Horse Association (http://www.lighthorse.org.au/)
The Great War, 1914-1915: a collection of photographs taken by Signaller J.P. Campbell whilst on active service with the glorious 3rd Brigade of Light Horse ... (http://nla.gov.au/nla.pic-an22966612)
This plume became the symbol of the lighthorse, inseparable from its legend.
Appreciating a practical joke, when asked about their plumes, First AIF light horsemen pulled many legs by replying that they were, in fact, "kangaroo feathers", placing the plume in the same vein as bunyip farms, walking-stick farms, and treacle mines.
It was not until the re-organisation of the militia forces in 1930, that members of lighthorse units were again allowed to adopt the plume as part of their uniform.