Irish President Michael D Higgins has hailed the transformation of relations between Britain and Ireland, from a period of doubt to trust and mutual respect.
In a historic address to the Houses of Parliament - the first time Ireland’s head of state has been given the honour - Mr Higgins said the two countries now have a closeness that once seemed unachievable.
He said Britain and Ireland must take pride in the peace that has been built in Northern Ireland.
“I am conscious that I am in the company here of many distinguished parliamentarians who have made their own individual contributions to the journey we have travelled together,” he said.
“I acknowledge them and I salute them, as I acknowledge and salute all those who have selflessly worked to build concord between our peoples. I celebrate our warm friendship and I look forward with confidence to a future in which that friendship can grow even more resolute and more productive.”
In a wide-ranging speech, President Higgins touched on many of the themes which his four-day official state visit to Britain will explore, including emigration and shared history.
The significance of the President’s visit is further deepened by the invitation for him to stay at the Queen’s home, Windsor Castle, where a state banquet is being held in his honour tonight and the presence of Northern Ireland Deputy First Minister and ex-IRA commander Martin McGuinness at the royal dinner - a move unthinkable only a decade ago.
The President, who is a poet, academic, intellect, human rights activist and football fan, addressed peers and MPs in Parliament’s Royal Gallery, flanked by floral displays in green, white and orange.
Prime Minister David Cameron, Deputy Prime Minister Nick Clegg and Labour leader Ed Miliband were in the audience.
Also among the MPs watching the address were Sinn Fein’s Pat Doherty, Michelle Gildernew and Paul Maskey, who do not take their seats in the Commons.
Northern Ireland Secretary Theresa Villiers was joined by predecessors in the role including Peter Hain.
President Higgins paid tribute to the UK Parliament for being synonymous with the principle of democracy and used his address to urge politicians to look at the foundation of parliamentary democracy in Britain for inspiration, referencing the Magna Carta and its significance for modern nations.
He said politics, society and the economy cause division between the citizen and the state when they are treated as separate entities and he urged polticians to remember that citizenship should be rooted in the principles of active participation, justice and freedom.
“Such a vision of citizenship is shared by our two peoples,” the President said.
“It is here, in this historic building, that, over the centuries, the will of the British people gradually found its full democratic voice. It is inspiring to stand in a place where, for more than a century, many hundreds of dedicated parliamentarians, in their different ways, represented the interests and aspirations of the Irish people.”
The President was a Labour politician for several decades before voted in as head of state with the largest ever single vote in the election in 2011.
He acknowledged that the fight for Irish independence - which his father took part in - cast a long shadow over Anglo-Irish relations but also noted how ties across the Irish Sea are now stronger than ever.
“We acknowledge that past but, even more, we wholeheartedly welcome the considerable achievement of today’s reality - the mutual respect, friendship and cooperation which exists between our two countries,” he said.
“That benign reality was brought into sharp relief by the historic visit of Queen Elizabeth to Ireland three years ago. Her Majesty’s visit eloquently expressed how far we have come in understanding and respecting our differences, and it demonstrated that we could now look at each other through trusting eyes of mutual respect and shared commitments.
“The ties between us are now strong and resolute. Formidable flows of trade and investment across the Irish Sea confer mutual benefit on our two countries. In tourism, sport and culture, our people to people connections have never been as close or abundant.”
Mr Higgins recalled the old ghosts of Irish nationalism, from 18th century emancipator Daniel O’Connell MP to the Home Rule bid to Irish freedom fighter and abstentionist MP Constance Markiewicz - the first woman elected to Westminster in 1918.
He said O’Connell’s ideals helped to guide and influence the achievement of the Good Friday Agreement of 1998.
“That achievement was founded on the cornerstones of equality, justice and democratic partnership, and was a key milestone on the road to today’s warm, deep and enduring Irish-British friendship,” he said.
“Our two countries can take immense pride in the progress of the cause of peace in Northern Ireland. There is of course still a road to be travelled - the road of a lasting and creative reconciliation - and our two governments have a shared responsibility to encourage and support those who need to complete the journey of making peace permanent and constructive.”
With Britain and Ireland celebrating a series of centenaries over the next few years, the countries’ shared history is a key part of the themes around the state visit.
Mr Higgins recalled the words of Irish nationalist MP Tom Kettle, who fought along with 200,000 Irishmen in the First World War, 50,000 of whom died, and who wrote that “this tragedy of Europe may be and must be the prologue to the two reconciliations of which all statesmen have dreamed, the reconciliation of Protestant Ulster with Ireland, and the reconciliation of Ireland with Great Britain”.
Kettle later wrote of his hope for relations between Britain and Ireland: “Free, we are free to be your friend.”
Mr Higgins said: “The journey of our shared British-Irish relationship towards that freedom has progressed from the doubting eyes of estrangement to the trusting eyes of partnership and, in recent years, to the welcoming eyes of friendship.”
He also paid tribute to the Irish emigrant community in Britain.
“That community is the living heart in the evolving British-Irish relationship. I greatly cherish how the Irish in Britain have preserved and nurtured their culture and heritage while, at the same time, making a distinctive and valued contribution to the development of modern Britain,” he said.
Commons Speaker John Bercow said the President’s address at Westminster was a “historic” day which “would have been difficult to imagine a few decades ago”.
In his introduction he said the visit had been described as “symbolic” but “in this case there is real substance wrapped inside the symbolism”.
He said: “The past is a powerful force but we should not allow ourselves to become prisoners of it.
“The progress made in Northern Ireland over the past 20 years, for all its imperfections - some of which still persist - should serve as an eternal reminder that with sufficient determination on all sides, progress can be both achieved and entrenched.”
Lord Speaker Baroness D’Souza described the President as a “renaissance man for a renaissance era in UK-Irish politics”.