Around 2,000 veterans gathered at the National Memorial Arboretum in Staffordshire for the service on Wednesday.
Operation Banner, the lengthiest continuous campaign in British military history, lasted from August 1969 to July 2007.
Among the veterans at the service was gunner Paul Thomas Haigh who served a tour with the Royal Artillery in Belfast, in 1974.
His unit was billeted in what he jokingly called the “luxury” of the Grand Central Hotel.
Mr Thomas Haigh recalled “a lot of noise, protests and banners” around places that would become synonymous flashpoints in the story of The Troubles including the Falls Road and Divis Road flats areas, but added it was also “quite adventurous”.
He added: “I tried to treat them (the people) right, and they were all right, I found.
“They were just as frightened as us, really, and all just wanted to live their life in peace.”
Asked if he felt the deployment had made a difference, he added: “We were there to stop Catholics and Protestants fighting each other, and they turned against us.
“I don’t get the logic of that, but it’s politics, isn’t it?”
Speaking about the importance of the commemoration, the retired 64-year-old, from Coventry, said: “We should remember the people who have fallen there to keep the peace.”
But he also spoke of his anger at what has been called a “witch hunt” by other veterans, regarding the prosecution of former military personnel who served in Northern Ireland.
“I’m very angry and disgusted by what our Government is doing,” he said.
“I don’t know why they’re doing it, because it’s been investigated before.
“I think it’s political.”
Another veteran attending was Paul Newton, 52, who was an RAF medic who served a three-year tour in Northern Ireland at RAF Aldergrove.
Looking back on his service, he said: “You think I’m still serving in the UK, dealing with people who carry a British passport but who want to throw rocks at me, call me names.
“Being vigilant about who you talked to, what might be round the corner.
“Nothing prepared you for that.”
Mr Newton, in his early 20s at the time, added: “As a medic, I’ve been out to situations where there have been bombings.
“You become very mechanical in your first aid, treating people to make sure they’re OK and have life-saving treatment.
“But there are times when I still think, ‘I wonder what happened to the guy who lost both his arms and leg or how the helicopter crash got on’.”
He had one particular memory of a young soldier who had a breakdown and was awaiting repatriation.
“He literally completely lost the plot, suffering really badly, mentally,” said Mr Newton.
“I’d met him previously and remembered what sort of a different man he was and how he’d been quite happy-go-lucky and jolly.
“And for him to be that broken person, and to see that, was very harrowing.”