It was an historic encounter to mark the Queen’s diamond jubilee. Her Majesty herself paved the way last year when she visited the Republic of Ireland with pacifying words and gestures.

But if then she tempered the sentiments of critics of the monarchy, today she won them over, shaking McGuinness’s hand, first away from the media, then in public.

McGuinness, Northern Ireland’s deputy first minister, held the Queen’s hand for a few moments, and said in Irish, “goodbye and God’s speed”.

McGuinness was a senior figure of the Irish Republican Army when it killed the Queen’s cousin Lord Mountbatten in a bomb blast in 1979.

The Queen heads Britain’s armed forces, which has been viewed in the past as occupying troops in the Republic and Northern Ireland.

Yesterday, the queen visited the former garrison town of Enniskillen, setting foot in a Catholic church in Ireland for the first time.

The town’s name is forever linked with the atrocity of 1987 when an IRA bomb killed 11 people in a crowd gathered for a Rememberance Day service at the town’s war memorial.

But the town buried its hurt as people from both sides of the divide cheered the Queen and Prince Philip as they drove to the church, amid fans waving Union Flags.