As dawn broke, families of soldiers, leaders and visitors gathered near former battlefields, honoring thousands of Australians and New Zealanders who fought in the World War I Gallipoli campaign on the 100th anniversary of the ill-fated British-led invasion.

Britain's Prince Charles and the prime ministers of Australia and New Zealand spoke of the soldiers' heroism on Saturday, in an emotional ceremony marking the centennial of the dawn landings by Australian, New Zealand and other Allied troops on this peninsula.

The landings at Gallipoli marked the start a fierce battle that lasted for eight months. Around 44,000 Allied troops and 86,000 Ottoman soldiers died.

The doomed offensive aimed to secure a naval route from the Mediterranean to Istanbul through the Dardanelles, and take the Ottomans out of the war.