President Michael D Higgins will begin an official state visit to Britain on Tuesday with the head of state heralding a new era of relations between the two countries.
His extended four day trip, three years after Queen Elizabeth II visited Ireland, will include an address to the Houses of Parliament and a focus on the contribution Irish emigrants have made to UK life.
On his departure Mr Higgins said the trip - the first ever by Ireland's head of state - was about remembering the past but also examining the capacity of the present and what can be done in the future to cement relations.
"We are at a very interesting point in history, when we have, following Her Majesty's visit to Ireland, such good relations between our people," he said.
"My hope for the visit at the end of it all is that people will in ever more numbers come to share in experiencing the history, the present circumstances and culture, and do so in ever greater numbers."
The theme of the state visit will be on the two countries' shared histories.
And the significance has been further deepened with the presence of Northern Ireland Deputy First Minister and ex-IRA commander Martin McGuinness who will attend a banquet hosted by the Queen - a move unthinkable only a decade ago.
Despite massive media interest in Ireland, it is hoped the momentous occasion will not be overshadowed by royals on the other side of the world, with Prince George threatening to steal the limelight Down Under as he is on tour with the Duke and Duchess of Cambridge for the first time.
Mr Higgins, who is accompanied by his wife Sabina, addressed the Northern Ireland peace process before he left amid wider discussions about how to deal with the past.
He said it would be wrong to wipe the slate clean over historic conflict which affected relations between Britain and Ireland and that progress should not be about forgetting the past.
"The peace process is that, it is a process that comes after the formal agreement at one level. Ultimately it is an exercise in consciousness at the level of community," Mr Higgins said.
"The challenge is to hand to a future generation all of the prospects of the future. You are not inviting them to an amnesia about any deep dispute.
"There are a lot of very difficult memories and it would be to my mind wrong to suggest to anyone that you should as it were, wipe the slate clean.
"I think Her Majesty in coming to Ireland and addressing for example issues of relations between our two people was doing it the right way."
The highly successful state visit to Ireland by the Queen and the Duke of Edinburgh in May 2011 paved the way for the return by Mr Higgins and makes the attendance of Mr McGuinness at the royals' home, Windsor Castle, the latest in a series of recent milestones in Anglo-Irish relations.
In remarkable scenes, the Queen paid her respects to republican dead at Dublin's Garden of Remembrance, visited Croke Park - site of the 1920 Bloody Sunday massacre - and made a widely-praised speech on Anglo-Irish history at Dublin Castle.
Since then, a number of meetings between Mr Higgins - a former Labour government minister, a poet and academic - and members of the Royal Family have taken place.
Although the Irish head of state has travelled to events in London, Manchester, Liverpool and Scotland last year, these were not official visits.
Mr Higgins will spend four days on the extended visit as a guest of the monarch, a sign he says is symbolic of the importance both countries place on the normalisation of relations more than 90 years after independence.
Despite the feelgood factor around the trip in general there is discomfort in some staunch conservative circles about Mr McGuinness' presence.
Efforts to cement reconciliation between republicans and the state took a massive leap forward when the senior Sinn Fein figure shook hands with the Queen during a trip to Belfast two years ago.
He was given the green light to join the latest celebrations after a meeting of the leadership of his party at the weekend even though they snubbed the ground-breaking royal visit to Ireland in 2011.
Highlights of the visit which begins with a ceremonial arrival at Windsor Castle will include the President's address at Westminster - another first for an Irish head of state.
Mr Higgins will also get to view the colours of disbanded Irish regiments in the British army while in Windsor.
In an interview with state broadcaster RTE, he praised the royal for setting the scene for the return visit and a new era of Anglo-Irish relations in her speech at Dublin Castle.
"The words chosen and the symbolic way they were delivered by the Queen herself were extraordinarily important," he said.
"The decision for example not to ignore the past but to address it, to go on and say as well, not only would things have been done differently but maybe not all, that was adding generosity to a kind of an ethic of memory."
Mr Higgins said it was an invitation to people to be firm about events in the past but not be crippled by them in the present.
Elsewhere, the President will visit the Royal Shakespeare Company in Stratford-upon-Avon and he will attend another major dinner at the Guildhall in the City given by the Lord Mayor.
He will also meet Prime Minister David Cameron in Downing Street during the visit and pay tribute to the work of Irish health professionals, meet business leaders and London Mayor Boris Johnson.
Northern Ireland will be recognised with the Queen hosting a reception for leading figures from Ulster's cultural, political and business life.
The President will be joined on the trip by Taoiseach Enda Kenny and Foreign Affairs Minister Eamon Gilmore.