Anglo-Irish relations took a momentous step forward today when the Queen shook hands with Sinn Fein's Martin McGuinness - twice.
Symbolically dressed in green and wearing white gloves, the smiling monarch held the hand of the former IRA commander for almost four seconds. They maintained eye contact and chatted throughout.
The first shake took place in private, away from the glare of the media - but the second was public.
Hands of history: The Queen's gloved hand held Mr McGuinness's for four seconds
Prince Philip can been seen behind the Queen shaking hands with McGuinness
During the second meeting, which is pictured, a "relaxed" Mr McGuinness spoke to the Queen in Irish and told her the words which meant: "Goodbye and God's speed." He told reporters afterwards it was: "very nice".
Prince Philip, who also shook Mr Guinness's hand, appeared to be smiling during the historic moment.
The historic encounter between the pair was unthinkable a little over 10 years ago. Even last night there was violence in Belfast as petrol bombs were thrown at police.
Mr McGuinness was a senior member of the IRA when it killed the Queen's cousin Lord Mountbatten in a bomb blast in 1979.
But the success of the peace process and the Queen's acclaimed visit to the Republic of Ireland last year, when her conciliatory words and gestures won over many critics of the monarchy, paved the way for their meeting.
They met in a room within Belfast's Lyric theatre during an event celebrating the arts in the Republic and Northern Ireland.
It is understood that during the VIPs' initial private meeting, Mr McGuinness welcomed both the Queen and President Higgins in Irish.
The Deputy First Minister is said to have commented briefly on the Queen's visit to Dublin last year, and in particular her comments regarding all the victims of the conflict.
TWITTER REACTIONS TO THE FAMOUS HANDSHAKE:
A Sinn Fein spokesman said: "He emphasised the need to acknowledge the pain of all victims of the conflict and their families."
Mr McGuinness is said to have spoken to the Queen of the significance of her visit, and of the need for it to be built upon in the time ahead.
Sinn Fein said Mr McGuinness told the Queen that their meeting was a "powerful signal that peace-building requires leadership".
Northern Ireland Secretary Owen Paterson met Mr McGuinness this morning and added that he was relaxed.
He said the Deputy First Minister greeted the Queen in Irish and their meeting was cordial.
"It had obviously gone very well," he said.
"This will move Northern Ireland on to a whole new plane. After all the trauma of Northern Ireland, everyone is looking forward.
"It is about a shared future, not a shared-out future."
The Queen is the head of Britain's armed forces, seen in the past by Republicans as occupying troops in Northern Ireland.
In a quiet space used by the Lyric for creative learning, the two met and were joined by the Duke of Edinburgh, Northern Ireland First Minister Peter Robinson, Irish President Michael D Higgins and his wife Sabina.
The McGrath Suite - named in honour of benefactor Harvey McGrath, former chairman of British insurer Prudential, and his wife Allison - is usually filled with toddlers enjoying story-telling sessions or drama students taking part in workshops.
But today it was sparsely furnished with leather seating - four chairs and a sofa - set around a circular wooden table decorated with flowers, with tea, coffee and still and sparkling water on a side table.
The floor-to-ceiling windows looking out on to landscaped gardens and the River Lagan were covered with curtains.
Asked how David Cameron viewed the handshake, the Prime Minister's official spokesman said: "Clearly, there was a visit by Her Majesty to the Republic of Ireland last year. That has taken relations between the two countries to a new level.
"We think it is right that the Queen should meet representatives from all parts of the community."
Former prime minister Tony Blair, who oversaw the Good Friday Agreement, welcomed the Queen's handshake with Mr McGuinness.
"I think it is fantastic that we have come so far," Mr Blair told the Evening Standard.
"The Queen's is a magnificent gesture and thoroughly typical because it must be very difficult for her - it is a sign of how much has changed."