Terry Langlands was just 23 years old when he was killed in action during the Vietnam War.
Dozens of the New South Welshman's old military training classmates will gather in Canberra on Sunday.
His story will feature in the Last Post Ceremony at the Australian War Memorial, where roughly 50 members of his graduating class are expected to attend.
Langland's brother and his daughter will lay a wreath at the ceremony.
Langlands, a keen sportsman and commerce student who grew up around Lake Macquarie, volunteered for national service after he was not picked in the initial 1965 draft.
The born leader was soon sent off to the Officer Candidate School in Scheyville, where he earned the nickname "Brindle" after trying to darken his slouch hat's brown leather chinstrap with black boot polish.
Langlands volunteered for immediate service in Vietnam in March 1968 rather than waiting for deployment.
His battalion was involved in several operations and he spent plenty of time in the bush.
In the early hours of November 24, Langlands and his platoon were in Phuoc Tuy Province when they came under fire from nearby bunkers.
Langlands was going to the aid of a soldier wounded by a detonated claymore mine when he was shot by a lone Viet Cong soldier standing out in the open.
When the platoon's medic arrived, Langlands ordered him to look after another soldier who had been hit.
Langlands and the second officer both died at the scene, with his remains later returned to Australia.
