Like many young men in 1914, Guy de Pierres was quick to enlist when war broke out.
But when the Wyalkatchem farmer left Fremantle on SS Malwa, he was destined for service in the French army as one of hundreds of French and Belgian-born Australians who served their birth nations in World War I.
For military historian and Vietnam veteran Paul de Pierres, his grandfather's story inspired two years of painstaking research.
It resulted in Allies Forever, a new book detailing the Francophone soldiers' stories and military records.
"He was descended from French nobility and had the hereditary title of Viscount," Mr de Pierres said of his grandfather.
"But he was an adventurer and farmer at heart. He wanted to get as far away from cultured French society as he could."
Guy was joined by his brothers Charley and Stephane, both of whom came with him to Australia, in enlisting.
Taking advantage of his British-French citizenship, Charley served the British army as an intelligence officer before losing an eye at the Battle of the Somme.
He stayed in France after the war, eventually fighting in the resistance against nazi Germany.
"Stephane was killed in the Vosges Mountains in Eastern France," Mr de Pierres said.
"The day he was killed he won the Legion of Honour in bitter hand-to-hand fighting."
The book has compiled a string of poignant stories, with men travelling halfway around the world out of a sense of patriotism and duty.
Andre Gabriel, then head of Michelin Australia, had just married his Australian wife when war broke out. An infantry sergeant, he was killed by a German artillery barrage at the Battle of Verdun in April 1916.
Others were battle-hardened veterans with a number of Australians serving in France's storied Foreign Legion.
Joseph Lalor, grandson of Eureka Stockade leader Peter Lalor, carried his grandfather's famous sword through Legion service in South America before he was killed at Gallipoli.
The book has won praise from French officials in Australia and will be part of a special exhibition at the French consulate in Sydney this year.