George Hubert Wilkins chose a splendid word to describe his profession when he signed up for World War I. "Explorer," he wrote.
He could have scrawled "adventurer". Or "scientist". Or "aviator". He was a child of the Heroic Age, that period at the beginning of the 20th century before war brought despair, when there was still plenty of the Earth to explore.  
Wilkins spent his life adventuring and taking risks that would leave the most extreme of today's thrill-seekers quaking. 
Raised in dry rural South Australia, he ran away to join a travelling picture show, took a camera to the Balkans Peninsula in 1912 to cover the war between Turkey and Bulgaria (where he pulled a revolver to stop a fellow correspondent from getting knifed), and spent three years sailing and traipsing the Arctic ice, happily surviving where quite a few of his fellow adventurers perished.
Yes, and he became Australia's most important war photographer in the dread of the Western Front in 1917 and 1918.
He'd forsaken his gun by then, instead lumping his heavy cameras into the most furious of battles right at the front, getting himself blown up and shot several times for his trouble. He captured the most authentic pictures of Australians at war (and, unlike any other war photographer, captured German prisoners, despite carrying no weapon), and won a Military Cross with Bar for acts of great courage.
Yet few enough of us now even know his name.
Oh, if you have any interest in Antarctica, you have heard of Wilkins Island, Wilkins Ice Shelf and Wilkins Sound. They were all named after him. He flew over a vast area of the Antarctic after the war.
In 1928, he navigated through the skies from Alaska to Norway over the Arctic Sea; something no one had previously done. He was knighted for it.
And those who have seen film of nuclear submarines rising through the ice at the North Pole might, if they studied hard, learn that Wilkins proved in 1931 that it was possible to take a clapped-out submarine beneath the polar ice cap. The US Navy was so grateful it took Wilkins' ashes and scattered them at the Pole when its first nuclear sub managed to burst through the ice in 1959.
George Hubert Wilkins ought, perhaps, be celebrated in Australia like Scott of the Antarctic is in Britain, the aviator Charles Lindbergh is in the USA, Everest summiteer Edmund Hillary is in New Zealand or Robert Capa, the war photographer acknowledged everywhere.
Until now, however, the real Wilkins has been all but a mystery. When the Melbourne-based historian and author Jeff   Maynard set out to write the definitive story of Wilkins, Australia's "unseen" World War I photographer, he discovered the vast bulk of material on this extraordinary character was stored, unread and all but forgotten, in the United States, where Wilkins had died alone in 1958.
Even the huge collection of World War I photographs at the Australian War Memorial proved a puzzle, for   Maynard discovered many of Wilkins' pictures were simply marked by an "unknown official Australian photographer" and others taken by him were identified as those of the more famous Frank Hurley. Hurley, himself an Antarctic explorer, was the other official Australian war photographer on the Western Front.
But Hurley fell out with Australia's war historian, C.E.W. Bean, because he liked to dress up his pictures, staging scenes and producing compositions with added explosions and even other battles to make them more dramatic. Bean was appalled. He wanted raw history.
After six weeks on the Western Front, Hurley took off for Palestine, and Wilkins stayed to slither through trenches, follow troops into shellfire, day after day, month after month, and capture pictures from warplanes under fire (he was commissioned in the Flying Corps).
He'd take himself and his camera and his glass plates hundreds of metres beyond the front to photograph Australian troops advancing, shellfire and bullets filling the air. He was first into villages, with Germans still there. Once he was buried when a shell burst next to him.
He was so willing to expose himself to danger to gather his pictures that the commander of the Australia Corps, General John Monash, called him "the bravest man in the AIF".
Yet Jeff   Maynard had to undertake his own expedition of discovery to piece together the story of Wilkins and his pictures.
Wilkins, it turned out, had collected and kept virtually every scrap of personal memorabilia - diaries, letters, manuscripts, pictures - during his life as photographer, polar explorer, aviator and adventurer (and botanist and meteorologist, for good measure).
But a complicated marriage led, after his death, to almost all this material being locked away in a dank Pennsylvania shed, fought over, turned into acrimonious legal battles, sold and split up.
The Ohio State University ended up with a mass of material - photos, correspondence and manuscripts fill 75 archive boxes alone.
  Maynard kept digging - and here is an adventure all on its own - he found in an old Amish barn in Michigan, 15 boxes containing a secret treasure of Wilkins material, including the key to identifying which World War I photos were his, and not some "unknown official photographer".
The result is a thrilling, wonderfully researched book. Every Australian should read it. Almost every page leaves you astonished.
The Unseen Anzac, by Jeff   Maynard (Scribe)