The Princess Royal joined National Service veterans and their families at the National Memorial Arboretum in Staffordshire to mark the 60th anniversary of the end of conscription.
Hundreds of veterans attended the special ceremony on Tuesday, commemorating the six decades since the last national serviceman was demobbed in 1963.
National Service saw more than two million young men conscripted following the Second World War, including 395 national servicemen who died while serving their country.
An average of 150,000 men were enlisted each year, for 18 months, but this was extended to two years during the Korean War before they finally became a reserve for four years.
While many served in the UK, tens of thousands were stationed worldwide, including in Iraq, Korea, Egypt, India, and Germany.
Conscripts experienced frontline combat in conflicts including the Suez Crisis, and the wars in Korea and Malaya.
John Bowler's conscription came as an unusual present on his 21st birthday, saying it was a bit of a shock when "I received a brown envelope which called me up to National Service.
"I knew it was coming but to arrive on your 21st birthday... Did me no harm, probably did me good.
"It gave me a chance to see a little bit of the world because they sent me to Malaya for six weeks."
For Brian Fuller, who served his time in the Royal Navy, it was also an opportunity to meet royalty.
He told Forces News: "I was working in the captain's office and we were the ship taken as the flagship to take the Royal party on a Royal cruise to the Channel Islands in 1949.
"So we had three days in the Channel Islands with Princess Elizabeth and Prince Philip on board and they had a wonderful time."
Veteran Peter Walker said National Service broadened his horizons.
He said: "There’s no doubt it changed my life in the sense that I grew up very quickly, as we all did.
"I think it improved my social ability, you're all suddenly thrust together with 40 kids who are exactly the same as you but come from all over the country, with lots of different values."
The event was the culmination of the national Ask Dad and Ask Grandad campaigns by the Royal British Legion (RBL) to find the "unsung heroes" of National Service.
Speaking at the service in Staffordshire, Princess Anne said: "Some thrived, others endured, but all were called upon to give up some of their time for this country and they did just that."