The Queen and Duke of Edinburgh will arrive in Northern Ireland today to start their two-day Jubilee regional tour.
During the trip, she will attend a service at St Macartin's Cathedral, in the town of Enniskillen where the 'Poppy Day Bomb' happened - an IRA bomb that exploded just before a remembrance service on 8 November 1987.
Eleven people were killed and dozens injured.
It is seen as a turning point in Northern Ireland's Troubles, the Enniskillen bombing was even condemned by the IRA's own supporters.
ITV News' Royal Correspondent Tim Ewart reports.
During the trip, the Queen is also expected to have a historic meeting with Stormont deputy First Minister and Sinn leader Martin McGuinness in Belfast on Wednesday.
Last year, his party boycotted the Queen's State visit to the Republic of Ireland.
Ahead of their meeting, Mr McGuinness said it would be a vital step in securing reconciliation between nationalists and unionists.
The Stormont deputy First Minister has been criticised by republican hardliners over the decision to meet the Queen, but he acknowledged how the royal family was bereaved by the IRA, as he said were other families across Britain.
The meeting will take place at a celebration of culture at the Lyric theatre in Belfast which will also be attended by President of Ireland, Michael D Higgins.
The Queen and Mr McGuinness are set to meet initially in private alongside a handful of VIPs and while a photograph of the moment was ruled out last week, sources have now said discussions are ongoing around allowing the handshake to be recorded.