The Gallipoli campaign, begun on April 25th 1915, was intended to assist British forces ultimately capture the Ottoman capital, Constantinople.
It was a failure.
Sixty thousands Australians fought Turkish forces at Gallipoli, alongside New Zealand, British, French, Indian and Newfoundland soldiers.
All suffered heavy casualties during the nearly eight month long campaign and the Anzacs failed to gain a centimetre of ground.
But National CEO of the Returned and Services League, Sam Jackman, said marking Anzac Day is now more popular than ever.
"Fundamentally Australians believe that the Australian psyche and the Australian spirit was born on the beaches in Gallipoli in 1915," she said.
Journalist and author of the book Gallipoli , Peter FitzSimons, said the idea of a modern Australian identity emerging from Gallipoli was unfortunate, but true.
"There was a tragic notion at the time that even though we had a constitution, even though we were federated, even though we had a parliament and all the rest, we weren't a real nation until we had shed blood," Mr FitzSimons said.
But Researcher Dr Carolyn Holbrook, the author of Anzac: The Unauthorised Biography said, legally and practically, Australia become a nation at Federation in 1901, not on the battlefield.
"People say that essential Australian values like sacrifice and mateship, suffering with your mates, that these kinds of things were born at Gallipoli, she said. "And that they embody the spirit of Anzac.
"That is simply not true."
More than 8000 Australians died during the Gallipoli campaign.
And there's concern that, 100 years later, as we honour the heroes, we forget the horrors.
Dr Holbrook said the commodification of the Anzac "legend" was at an all time high.
"We are currently at peak Anzac," she said.
"Everywhere you go at the moment, the post office, the supermarket, there is Anzac kitsch and Anzac memorabilia. It's propaganda really in a way," Dr Holbrook said. "If the soldiers could see some of the stuff that is going on they would be horrified."
Peter Fitzsimons said Australians often confused celebration with commemoration in remembering World War One.
"There is nothing to celebrate," he said.
"This was not a hairy-chested breast-beating moment, this was a real moment of our blokes, they weren't superhuman. They were ordinary men who accomplished extraordinary things."
Dr Carolyn Holbrook denied being unpatriotic, by trying to explode the Anzac "myth".
"There are barnacles that have attached themselves to the Anzac legend and we need to scrape off the barnacles and make sure the commemorations are actually about the soldiers and the tragedy of what they endured," she said.