Hundreds of ex-soldiers took part in a parade Saturday to mark 50 years since British troops were deployed to Northern Ireland.
The operation went on until 2007 and was one of the longest in the army's history.
The event, in Lisburn near Belfast, was organised by the Veterans Association of Northern Ireland.
At the height of the British presence in Northern Ireland, nearly 722 people died, in a region torn apart by community unrest.
Known as The Troubles, it pitted the majority Protestant population, who wanted Northern Ireland to remain part of the United Kingdom, against the Catholic minority, who believed the region should be part of the Republic of Ireland.
Nearly 10% of the 3,500 victims of The Troubles were killed by members of the army and police, AFP cites.
The United Kingdom is deeply divided as to the prosecution of the alleged crimes of soldiers, with supporters of the army opposing the holding of trials.
The Veterans Association of Northern Ireland said its members were "worried".
A peace agreement was signed in 1998, but, two decades later, democracy has stalled and Brexit threatens to open old wounds.
Recently, during the annual Apprentice Boys of Derry marches, band members were criticised for wearing 'Parachute Regiment' badges. The elite British army regiment is most closely associated in Northern Ireland as the group behind the 1972 Bloody Sunday killings, where 13 civilians were shot and killed by British troops during a civil rights protest.
One anonymous soldier was charged with murder in March of this year. Several loyalist groups expressed support for the so-called "Soldier F" following the conviction, with many seeing the Apprentice Boy's sporting of the Parachute Regiment badges as a sign of alliance.
Riots have been taking place in Derry throughout this week causing "unwanted disorder and destruction" according to Superintendent Gordon McCalmont. A total of 24 petrol bombs were thrown on Monday night alone said police.
Read more | [Northern Ireland conflict 50 years on: will a no-deal Brexit threaten the peace?](Northern Ireland conflict 50 years on: will a no-deal Brexit threaten the peace?)