Martin McGuinness, Northern Ireland's deputy first minister, will hold a landmark meeting with the Queen when she visits Belfast next week, his Sinn Fein party has confirmed.
The meeting comes following months of speculation about a formal encounter between royalty and republicans.
Sinn Fein refused to agree to a meeting linked to the large-scale jubilee party which is to be held in the grounds of Stormont, the Belfast seat of government.
Although the party has brushed aside many of its old taboos in recent years, it clearly drew the line at having McGuinness associated with the spectacle of more than ten thousand flag-waving royalists.
"This will understandably cause difficulty for republicans and nationalists, especially those who have suffered at the hands of British forces," said Sinn Fein president Gerry Adams.
But he added that the move reflected a "genuine desire to embrace our unionist neighbours".
It was announced that the Queen will meet McGuinness, a former IRA commander, in an Anglo-Irish setting rather than at a specifically British event.
The organisation said it would invite "a small number of guests to recognise and celebrate the transformational strength of the arts and culture across the community in Northern Ireland and throughout Ireland."
Those invited will include McGuinness and his unionist partner in government, first minister Peter Robinson.
The Queen, who is due to visit Northern Ireland on Tuesday and Wednesday, is joint patron of Co-operation Ireland with Irish President Michael D. Higgins.
The Sinn Fein decision was widely seen as inevitable since the republicans are regarded as having missed a trick when they boycotted the Queen's visit to Dublin a year ago.
That visit was hailed as a resounding success and indeed a historic moment in Anglo-Irish relations, especially when the Queen dressed in green and, to general surprise and delight, spoke several words of Irish in a speech.
She was applauded for being prepared to consign decades of Anglo-Irish friction to the past. In meeting Mr McGuinness she will be aware that the organisation he once led assassinated her relative, Lord Mountbatten.