The army's 38-year presence in the province left a bitter legacy in the form of a fierce political debate over whether soldiers should be prosecuted for alleged crimes.
Since soldiers first appeared on Northern Ireland's streets on August 14, 1969, the British army witnessed and was involved in some of the darkest hours of the Troubles, the three decades of unrest in the province.
Troops were initially brought in to help police deal with inter-community rioting in Londonderry and Belfast, in what was intended to be a short intervention.
When it ended, Operation Banner had become the British army's longest continuous deployment.
Saturday's event was due to feature military and religious services.
A heavy police presence was in place and the parade was under high security.
Organisers have tried to put the focus on those who lost their lives during Operation Banner, not just those killed in action, but others who died through accidents or stress-related suicides afterwards.
Northern Ireland's former first minister Arlene Foster and widows of the bereaved were among those in attendance.
Some 10 per cent of the 3,500 victims of "The Troubles" were killed by members of the military and police.
Prosecutions and inquiries over killings are still ongoing, dividing British and Northern Irish society over whether and how justice should be sought.
The Northern Ireland Veterans Association is holding an anniversary memorial event in the city of Lisburn, southwest of Belfast.