Martin Meehan, the veteran Ardoyne republican, comes from a hard school. On the run in my home town of Dundalk in the early 1970s he and his cohort Dutch Doherty once boasted: “We engaged the British Army last night and they squealed like pigs.” Now he was talking of his joy at finding the grave of a British soldier in Belgium.

“A precious treasure,” he called it, a catch in his voice as he described weeping over the plot, on which he poured holy water and scattered soil from his mother’s burial ground. The grave contained the body of his grandfather Camillus Clarke, one of 50,000 Ulstermen to die in the first world war.

Meehan remembers his mother telling him that as a young girl she had once been given a poppy on Remembrance Day and had worn it in the staunchly nationalist Bone area. Everybody abused her, including her own relatives, but she refused to take it off, countering: “I’m only doing it for my father.”

The defiant gesture put an end to poppy-wearing in the Meehan household and, amid the Easter lilies and republican commemorations, the details of exactly what had happened to grandfather Camillus slipped out of focus until a few years back.

Then Meehan, by now a Sinn Fein MLA, met Roy Garland, a unionist writer who was completing a life of Gusty Spence, the former UVF leader convicted of the first sectarian murder of the Troubles. Meehan told Garland the story and Spence, an amateur military historian, found the Belgian village in which Camillus had fallen.

Last year, Meehan and a group of cousins set out to find and reclaim their lost ancestor. The grave was not easy to find, they had to split up to conduct the search and, as Meehan remembers, there were whoops of joy when it was located. There was no moral — just a sense of fulfilment and wholeness.

The remarkable story was told at an event organised by Coiste na n-Iarchimi, the Provisional IRA ex-prisoners’ group, which was also addressed by Chris Carson, the chairman of the British Legion, who admitted: “You wouldn’t have got anyone from the legion to come to this five years ago.”

Another republican former prisoner told me outside how, when he wanted to hear the story of his grandfather, he was told as a child: “Don’t be asking about that auld bastard.” He imagined his grandfather had abused the family in some way but later discovered that his only crime was to have died in the war.

One had a sense of lines being drawn tighter in the last 30 years of conflict than they were before. Republican and unionist versions of history paint a black and white picture of loyalists and rebels, but miss the fact that the categories were often porous, with people moving between them for reasons that are airbrushed from history.

At the event last week, Laurence McKeown, a former H-Block inmate and hunger striker, remembered being regaled by another blanketman with tales of his service in the British Army in Aden.

McKeown told how Paul Marlowe, who blew himself up with his own bomb in an attempted IRA attack on the British Army in 1976, was a former member of the SAS, while the veteran republican John Joe Magee was a former member of the British Army’s other elite force, the Special Boat Squadron.

He might have added, but didn’t, that Magee was the head of the IRA’s internal security department, the infamous Nutting Squad operating in the latter part of the Troubles. Magee’s No 2 in the squad, set up to root out British agents, was a British serviceman of another sort, Freddie Scappaticci who was known to his military intelligence handlers as Stakeknife.

In fact, so common were former soldiers within the IRA that the Force Research Unit, the British Army’s agent-handling unit, encouraged soldiers from republican areas to join the IRA when they demobbed and to work as agents within it. Willie Carlin in Londonderry was a case in point as was Kevin Fulton in Newry.

Times Recommends

• Fish and chip shops ‘selling cobbler as cod’
• T in the Park festival at Kinross
• How to get Madonna’s Thighs