By Mark Simpson
BBC Ireland Correspondent, at St Paul's Cathedral, London
Veterans honoured colleagues who served during the Troubles
Politics, religion and marching can be a dangerous combination but on this occasion - a special service to remember the soldiers who died in the Troubles in Northern Ireland - they came together with great dignity.
At a time when critics say the Army no longer receives the recognition it deserves, people from all parts of the UK came together at St Paul's Cathedral to pay their respects.
In particular, they honoured the 763 servicemen and women killed as a direct result of violence in Northern Ireland.
Known as Operation Banner, it was the longest campaign in British military history, from 1969 to 2007.
Army veterans and the families of those who died joined with prime ministers old and new at the special service at St Paul's Cathedral.
They swapped stories, and some shared old photographs.
John Heasley, 57, who served in the Ulster Defence Regiment in Newry, showed me his scars.
In 1976, he was hit by three bullets in his right leg, two in his left leg, one in his right arm and one in the back of his head.
"I just feel lucky to be here," he said, as he gazed up at St Paul's Cathedral.
As a local soldier serving in his home country, he was thankful to his comrades who were shipped over from England, Scotland and Wales.
"I came to the service today to say 'thank you' to all the soldiers who came over. Year after year, time after time, they did what they did."
So what would Northern Ireland be like if the Army hadn't stepped in?
"It would still be like 1972," he suggested.
That was the worst year of the Troubles - 496 people died, of whom 134 were soldiers.
It was also the year of Bloody Sunday when 14 unarmed civilians were shot dead by the Army.
That led many in the nationalist community to conclude that the troops were part of the problem, not the solution.
By their own admission, many of the soldiers knew little about Northern Ireland before they were sent over.
Eddie Atkinson from Skipton had barely been out of Yorkshire when he came over with the Green Howards regiment in 1971.
"We went over there to try to bring as normal a life to the locals as possible, and unfortunately by doing that, we ended up in the firing line."
His thoughts during the service at St Paul's Cathedral were about the friends who went to serve in Belfast but never came home.
Prince Charles salutes veterans at the remembrance service in London
A candle was lit in memory of the dead by Mary Moreland, whose husband John, a part-time soldier, was shot dead by the IRA just before Christmas in 1988.
She believes the conflict was a fight between "good and evil".
She said: "What we have to do is not live in the past but remember it. Don't let us rewrite history but let us remember it how it was."
It is a history covered in blood.
Northern Ireland isn't quite at peace, but the absence of troops on the streets is a sure sign that the so-called Troubles are over.
Indeed, a number of old soldiers now go to Northern Ireland for their holidays.
That, in many ways, says it all about how times have changed.