One of the most painful chapters in the Queen's life - the IRA murder of her cousin Lord Mountbatten - was acknowledged in her private talks with Martin McGuinness, it has emerged.
The Stormont deputy First Minister revealed that he addressed the 1979 murder when he met the Queen privately in Belfast last Wednesday.
The former IRA commander shared an historic handshake with the Queen in public at the city's Lyric theatre, but their conversation took place during an initial private meeting at the venue.
The handshake that made history: Martin McGuinness and the Queen
Mr McGuinness said he would not detail exactly what he said during the eight-minute discussion, which the Duke of Edinburgh also attended, or how the Queen responded.
"I said to them that I recognised that they too had lost a loved one," Mr McGuinness said.
"I did not shy away from the issue because I think these are things that we need to face up to.
"I will not repeat what she said as that would not be proper, but she was absolutely understanding of the need for everybody to work together to ensure that we don't go back to the past."
He added: "She was very gracious about it."
Mr McGuinness revealed some of the detail of the private meeting during a talk show on RTE television on Saturday.
Sinn Fein had previously said that during the meeting Mr McGuinness referred to the Queen's ground-breaking visit to the Irish Republic last year where she spoke of the need to remember all victims of the Troubles.
The party said Mr McGuinness had endorsed that view, but in his TV comments he went further and revealed he had raised the fact that the royal family had themselves suffered loss.
Lord Mountbatten was killed with three others when the IRA detonated a bomb on his boat as he holidayed in Co Sligo in 1979.
The former Viceroy of India, who was also the Duke's uncle, was killed on board a boat off Mullaghmore by an IRA gang using a radio controlled device.
One of Lord Mountbatten's twin grandsons, Nicholas, 14, and Paul Maxwell, 15, a local teenager employed to help on the boat, also died in the explosion.
An elderly relative of Lord Mountbatten, Lady Doreen Brabourne, was injured in the attack and died later.
The bombing was a major blow to the royal family and at a subsequent memorial service to his loved one, Prince Charles reportedly hit out at the "sub-human extremists" capable of such an act.
In advance of the handshake with the Queen, Sinn Fein was condemned by republican hardliners who cited the lives lost at the hands of the British military.
But the party's decision to hold the ground-breaking meeting has been widely welcomed.
Mr McGuinness said his handshake with the Queen was a means of reaching-out to all unionists in Northern Ireland.
Sinn Fein is already involved in discussions with leading figures in the Protestant community in Northern Ireland aimed at devising a way of healing the wounds left from the decades of violence.
But reports that this might amount to a fresh apology from the IRA for the people it killed during the Troubles were played down by Mr McGuinness.
He said reconciliation was vital, but required efforts by all sides in the conflict to deal with the legacy of the past.
Last week he followed his historic meeting with the Queen in Belfast by delivering a speech in London where he accused the British government of refusing to recognise its role in the Troubles.
Meanwhile, in a further political development Mr McGuinness has revealed agreement was reached on delivering a long-delayed forum to bring together parliamentarians from Belfast and Dublin.
The north-south parliamentary forum was one of the bodies promised in the 1998 Good Friday agreement.