The 40th anniversary of the official end of Australia's involvement in the Vietnam war will be marked in Canberra on Friday.
In 1973, then governor-general Paul Hasluck proclaimed the cessation of hostilities by the Australian government in the conflict.
From 1962 to 1972 more than 60,000 Australian men and women served in Vietnam.
More than 500 were killed in the conflict and another 3000 wounded.
But for those who returned home the psychological scars were possibly the worst.
Australian War Memorial head of military history Ashley Ekins said the proclamation of the war probably meant little to those when it was signed off by Sir Hasluck on January 11, 1973.
"It wasn't a big deal when it was announced back in 1973, simply a proclamation by the government by the governor-general," Mr Ekins said.
"But really the troops were out, it was all over for them."
Mr Ekins said it spelt the formal end of the most controversial and divisive war the nation had known.
The conscription of young Australians to fight the war, the anti-war movement and the reaction troops faced on their return left a lasting impact on Australia as a nation that is still felt.
At the Australian War Memorial in Canberra the anniversary will be marked with a short address during the closing ceremony where each day the Last Post is played by a bugler or a lament played by a piper to remember the sacrifice made by Australian troops.