THEY left Australia eager for adventure and to see the world.
Those first volunteer soldiers returned barely a year later, having witnessed nearly 9000 of their mates killed on the shores of a far-off place called Gallipoli.
The sacrifice of those 'Knights of Gallipoli' was honoured at the first Anzac Day, held on April 25, 1916.
Every state held ceremonies to honour the fallen.
In Sydney, 4000 returned men led a procession that included 50 cars bearing the injured.
It was a similar turn-out in Perth, where 'the men of The Landing' marched up The Esplanade before turning into the Central Railway Station, observed and cheered by hundreds along the route.
Melbourne, Brisbane, and Adelaide also hosted Anzac Day marches, while 2000 Australian and New Zealand troops marched in London.
After serving at Gallipoli, many of those who returned were expected to help recruit new volunteers at recruitment centres in nearby suburbs and towns.
Each man vowed to secure one new soldier.
To this day, Anzac Day marks the first landing of Diggers from the Australian Imperial Force at Gaba Tepe, now known as Anzac Cove, on April 25, 1915.
Twenty-thousand Australian soldiers landed just before dawn on the Gallipoli peninsula.
By nightfall, 747 of those soldiers would lie dead on the beach or close by in the surrounding steep cliffs, killed by Turkish troops under the command of Mustafa Kemal Atatrk.
These "worthy sons of the Empire" fought a piecemeal battle under mixed orders.
Successive Anzac Days remember their courage and boldness and provide a nation with an opportunity to reflect on our first major military action during World War I.
The Gallipoli campaign claimed the lives of 8000 Australian soldiers; in all, more than 60,000 Australians died during World War I.
It wasn't until the 1920s that Anzac Day became a day of commemoration.
The dawn service marks when the first wave of Anzacs stepped ashore at Gallipoli; the first such service was held as a requiem mass in Albany in 1918.
Anzac Day grew in the 1930s to include other events, such as playing two-up.
It was also a day for returned soldiers' reunions.
Canberra held its first Anzac Day service commemoration at the War Memorial in 1942.
This has become the centre for the nation's modern Anzac Days, with prime ministers and opposition leaders laying wreaths.
Thousands make the annual pilgrimage to dawn services held at Gallipoli.
More than 70 cemeteries dot the landscape, with many more unmarked graves in countless mass pits.