Northern Ireland’s First and Deputy First Ministers returned to the Belfast prison where they were both detained during the Troubles as they accompanied the Queen on a tour of the premises.
Once a forbidding facility synonymous with the dark years of the conflict, the transformation of the old Crumlin Road Gaol into a popular visitor attraction is symbolic of Northern Ireland’s journey toward peace.
There could have been few stronger validations of that theme than the sight on Tuesday of Her Majesty and the Duke of Edinburgh alongside First Minister Peter Robinson and Deputy First Minister Martin McGuinness in the corridors of the 19th Century building.
Sinn Fein veteran and former IRA commander Mr McGuinness was held in the prison for over a month in 1976 on a charge of IRA membership - a count that was later dropped in court.
DUP leader Mr Robinson was detained on a number of occasions during the 1980s for his involvement in protests against the controversial Anglo Irish Agreement.
Now leaders of Stormont’s powersharing administration, both men welcome the Queen and Duke this morning.
Earlier cheering crowds waving Union Flags greeted the Royal couple as they arrived. Once inside, Her Majesty and the Duke were taken on a guided tour of the 19th Century building.
Among those the Queen was introduced to was lottery millionaire from Belfast Peter Lavery, who is turning A Wing into a boutique whiskey distillery.
Among the cells they passed in C Wing was the room where 12 condemned prisoners were hanged.
Outside in the prison courtyard as the tour concluded the Royal couple were waved off by local schoolchildren.
The symbolic visit unfolded after the Queen on Monday night held her first one to one meeting with Mr McGuinness.
The private audience at Hillsborough Castle was the third encounter between Her Majesty and Mr McGuinness but the first on an individual to individual basis.
Images of the monarch and the high profile republican exchanging pleasantries and small talk as they walked slowly around the old prison on Tuesday morning would scarcely have been imaginable three years ago, never mind in the decades scarred by violence.
But the watershed moment in 2012 when Her Majesty and Mr McGuinness met for the first occasion, and shook hands, has paved the way for further strides to normalise relations between Irish republicanism and the British establishment in the post-conflict era.
Mr McGuinness described the Queen’s visit to the Crumlin Road prison as another “bold step” by the monarch.
“The vast bulk of our people appreciate the effort Queen Elizabeth is making to peace and the reconciliation process and I think many people will look at the visit to the Crumlin Road prison, for example, with a degree of astonishment,” he said.
The jail visit is the first engagement of five for the Royal couple in Belfast on Tuesday.
Their schedule also includes a tour of the set of hit US fantasy drama Game Of Thrones in east Belfast.
Much of the popular HBO series is filmed in the Painthall studios in the city’s regenerated docklands.
The Queen and Duke will also pop into the bustling St George’s Market in Belfast city centre, be guests at a reception and lunch at Belfast City Hall and attend a garden party at Hillsborough Castle.
The castle is also playing host to experts and crew from the Antiques Roadshow this week and the Queen and Duke will stop by to visit them on Wednesday.
During her time across the Irish Sea, Her Majesty will also attend a Royal British Legion reception in Coleraine in Co Londonderry where she will launch a programme of activities commemorating the First World War.
As with a range of recent royal engagements involving Ireland, both north and south, the themes of reconciliation, regeneration and focusing on the future are being emphasised during what is the Queen and Duke’s 21st visit to Northern Ireland.
While past trips have seen the Queen’s itinerary closely guarded due to security fears, this week’s engagements in the Province have been publicised in advance.
The Queen and Duke last visited Northern Ireland in 2012 as part of Her Majesty’s Diamond Jubilee celebrations.
That occasion proved highly symbolic in terms of the peace process as it marked the first occasion she met Mr McGuinness.