"It puts it all in perspective to come here," Peter Crowle, 69, whose grandfather died in the battle, told AFP. "The conditions they were subjected to were hell on earth."
The governor general of Australia, Sir Peter John Cosgrove, will be among the dignitaries on hand for the ceremonies in the town of Villers-Bretonneux recalling the nearly five-month battle in 1916, which saw more than a million casualties on both the Allied and German sides.
It is "an opportunity to remember more than 102,000 who have given their lives for our nation," Major General Dave Chalmers of Australia's veterans affairs department told AFP.
The Battle of the Somme came to symbolise the futility of World War I. Each of the 141 days of trench warfare led to some 8,500 casualties, but for all that the Western Front shifted no more than a few kilometres.
For the Australian volunteers, the sacrifice began with a sea journey lasting up to four months, and those returning alive were but "mangled human freight", as one poet of the time described them.
The spirit shown by the Anzac troops has long been seen as critical in forging a national identity in Australia as well as in New Zealand, both fledgling nations at the time.
Anzac Day commemorates the landing of the Australian and New Zealand Army Corp (ANZAC) on the Gallipoli peninsula on April 25th, 1915, at the start of an eight-month campaign against the Ottoman Empire in which 8,700 Australians and nearly 2,800 New Zealanders died.
The battle of Gallipoli is generally seen as a devastating military failure for the Allied powers against the German-backed Ottoman forces, who managed to resist the attempts to break through towards Constantinople.
Now synonymous with valour, Anzac Day is a public holiday in both Australia and New Zealand, also honouring veterans from other conflicts, including South Korea, Malaysia, Indonesia, Vietnam and Iraq.
Held across Australia, the Anzac dawn service has its origins in a military practice known as "stand-to", in which soldiers are woken before dawn to avoid the vulnerability that comes with the early light, which is notorious for playing tricks on the eyes.
The history also runs deep in the community in northern France where so many lost their lives.
"Over the past century the bonds of friendship between the residents in towns like Villers-Bretonneux and Australians have only strengthened," Chalmers said.