Coronation: How the relationship between British royals and Irish republicans has entered a new era

King Charles will find two things in Northern Ireland - his most loyal subjects and his least loyal subjects.

Unionists will mark his coronation by proclaiming themselves "as British as Finchley" - Margaret Thatcher's commitment to Northern Ireland in 1981.

Nationalists will be largely apathetic to the pomp and circumstance. But the attitude of some about the monarchy has revolutionised.

Queen Elizabeth's jubilee visit to Northern Ireland in 1977 was her last for 14 years due to the terrorist threat.

In 1979, the IRA murdered her cousin, Lord Mountbatten, by detonating a bomb on his boat off the Irish coast.

But four decades later, Sinn Fein deputy leader Michelle O'Neill has accepted an invitation to attend the coronation in London.

Ms O'Neill, the first nationalist to be elected first minister-designate in Northern Ireland, said: "We live in a changing space".

"There's no doubt republicanism and the monarchy, they are two things that are very much at odds but again, I think that's just the world we live in," she added.

"We live in a changing space and… it doesn't diminish my republicanism to attend the coronation of the King and be respectful to those people here of a British identity," she added.

Michelle O'Neill warmly expressed her sympathy to King Charles when he visited Northern Ireland following the death of Queen Elizabeth.

He thanked her for "the incredibly kind things" she had said about his mother and her contribution to peace in Northern Ireland.

Queen Elizabeth's historic visit to the Republic of Ireland in 2011 signalled a new era in Anglo-Irish relations.

She used very few words, but they were spoken in the Irish language, a hugely symbolic gesture of reconciliation.

"A Uachtarain agus a chairde" - translated as "President and friends" - won rapturous applause as Her Majesty opened her state banquet speech in Dublin.

The Queen continued: "To all those who have suffered as a consequence of our troubled past, I extend my sincere thoughts and deep sympathy.

"With the benefit of historical hindsight we can all see things which we wish had been done differently or not at all."

A year later, she publicly shook hands with Northern Ireland's then deputy first minister Martin McGuinness, a former IRA commander.

A conciliatory handshake is one thing; Sinn Fein's presence at the coronation of a British King is quite another.