The historic handshake between the Queen and Sinn Fein's Martin McGuinness, together with his words of blessing as they said goodbye, have been hailed as a watershed moment for Anglo-Irish relations.
The encounter between the former IRA commander - now Northern Ireland's Deputy First Minister - and the Queen was unthinkable a little over 10 years ago.
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.
The Queen and Mr McGuinness first shook hands away from the media spotlight behind closed doors at a cultural event in Belfast's Lyric theatre.
But as the Queen left the venue they shook hands again, this time in public, as Mr McGuinness offered parting words in Irish and told her the phrase meant: "Goodbye and God's speed."
During their initial private meeting the Deputy First Minister is said to have commented briefly on the Queen's visit to Dublin last year, and in particular the comments she made at the time recognising all the victims of the conflict.
A Sinn Fein spokesman said of their conversation: "He emphasised the need to acknowledge the pain of all victims of the conflict and their families."
Their historic first meeting took place in a room within the Lyric theatre during an event celebrating the arts in the Republic and Northern Ireland.
They were joined by the Duke of Edinburgh, Northern Ireland First Minister Peter Robinson, Irish President Michael D Higgins and his wife Sabina.
The Queen ended her two-day visit to Northern Ireland by appearing at a party held in her honour in the Stormont estate which was attended by 20,000 people.