Britain’s Queen Elizabeth II will meet Martin McGuinness, former Irish Republican Army commander and current deputy first minister of Northern Ireland, for the first time next week, the IRA’s political party said, marking a milestone in the province’s peace process.

The queen has never met a senior figure from the now-defunct IRA, which killed her relative Lord Mountbatten in 1979, or Sinn Fein. The party decided Friday to sanction the meeting, which would have seemed inconceivable a generation ago.

McGuinness, a hero among Irish nationalists who fought a bitter three-decade war against British rule, will meet the 86-year-old monarch Wednesday during a two-day visit to Northern Ireland as part of her Diamond Jubilee celebrations.

“Today’s decision is the right thing to do, at the right time and for the right reasons,” said Sinn Fein President Gerry Adams, who, alongside McGuinness, helped end the years of sectarian violence and win an equal voice for Roman Catholics in a power-sharing government with former Protestant foes.

He added that the party’s decision was not unanimous but that a clear majority were in favor of the meeting. He also said McGuinness would “of course” shake hands with the queen.

The IRA ended its 30-year armed campaign against British rule in 1998, but splinter groups have continued to launch attacks on British targets, prompting security concerns that have prevented the queen from publicly announcing trips to the province ahead of her arrival.

This visit is the first to be announced in advance since violence broke out in the 1960s and will see the queen and her husband, Prince Philip, travel to Belfast and Enniskillen, scene of a deadly IRA bombing in 1987.

The queen will meet McGuinness; Peter Robinson, Northern Ireland’s first minister; and Michael D. Higgins, Ireland’s president, at an event organized by Co-operation Ireland, a cross-border, peace-building charity.

Adams stressed that the event was “unconnected with the jubilee.” allowing McGuinness to meet the queen on terms that were acceptable to his party.

Sinn Fein, which has become increasingly popular south of the Irish border as the main party opposing an EU/IMF bailout, has urged a referendum be held on whether Northern Ireland remain part of Britain where it deputies still refuse to take their parliamentary seats.

It also rejected invitations to attend events during the queen’s symbolic visit to the Republic of Ireland last year, the first by a British monarch since Dublin won independence from London in 1921.

The queen has made powerful gestures of reconciliation for Britain’s bloody past in Ireland, expressing regret for centuries of conflict, prompting one Sinn Fein mayor to break rank and became the first member of his party to shake the hand of the queen during the trip.

In a file picture taken on April 24, 2009, Martin McGuinness, Deputy First Minister of Northern Ireland, addresses the media in Londonderry, Northern Ireland. (PETER MUHLY/AFP/GETTY IMAGES)

The party has softened its attitude to the royal family since then, agreeing last month not to block Belfast’s government from giving the queen a present to mark the Diamond Jubilee, the 60th anniversary of her accession to the throne.

Last year, the party refused to support sending a gift for the wedding of Prince William and Kate Middleton.

“Today’s decision reflects a confident, dynamic, forward looking Sinn Fein demonstrating our genuine desire to embrace our Unionist neighbours,” Adams said.

“You can rest assured (though) that when Martin McGuinness completes this engagement, he will be as true and as staunch and as active a republican as he is now.” (Reporting by Padraic Halpin. Additional reporting by Lorraine Turner; Editing by Jon Hemming)