Almost 100 years after Gallipoli, mystery still shrouds the identity of one of the soldiers killed on the first day of the landings.
A new book traces the lives of the 101 ''lost boys'' who were in the first wave of soldiers to land at dawn on April 25, 1915.
The work is by Peter Stanley, a former principal historian at the Australian War Memorial, who seeks to tell the personal stories of this small group - where they came from and why they volunteered.
Professor Stanley comes close to achieving that aim. But on the last page of Lost Boys of Anzac he reveals that, after months spent chasing leads in Australia and Britain, and tramping the hillsides of Gallipoli, the full story of one soldier eluded him.
''It turns out for one of the Lost Boys, a man with the ordinary name of William Walker, of the 9th Battalion, we know almost nothing,'' he writes.
His attestation papers reveal Walker to be a 22-year-old Anglican labourer, originally from Buckinghamshire in England, who volunteered in Brisbane in August 1914. After that, there is very little. He is not mentioned in anyone's diary or any official file. There is no Red Cross file or roll of honour file. He has no grave, no photograph and his AIF file contains no letters from his family.
Professor Stanley writes that Walker disappeared as finally as any anonymous Ottoman soldier, and like them he lay unburied in the scrub of the peninsula.
''William Walker is not literally the Unknown Australian Soldier - his body was buried in France three years later. But, as a symbol of the Lost Boys of Anzac, William Walker exactly represents their tragedy.''
Professor Stanley said the men lost in the first wave of landings have carried the burden of our continuing desire to remember Gallipoli - but most Australians cannot name a single soldier who died on that day.
''They should no longer remain as abstractions in Anzac Day addresses. Their comrades, families and communities knew them as real people, not only as the embodiments of an Anzac legend that had not been named or formulated when they were alive.
''Now we know their stories, we can, at last, begin to think of them again as individuals; as real people who lived a century ago and who can live again in our imaginations.
''Anzac Day addresses talk about mateship and courage and loyalty - but the people who are saying that don't know the people they are praising. I am frustrated at the way Australians have a very partial understanding of the Anzac legend.''
Do you know more about William Walker?