President Michael D Higgins has led tributes to former taoiseach and Fine Gael leader Liam Cosgrave, who passed away last night aged 97.
He said that Mr Cosgrave was committed to serving the people of Ireland "with all of his energy, intellect as well as passion".
President Higgins said that he will be remembered as a taoiseach "with the capacity to win and secure the stability of a multi-part coalition".
In a statement, the President said: "Among his most memorable achievements was that as Minister for External Affairs, when Ireland's entry into the United Nations in 1955 was secured, and during which time Liam Cosgrave gave shape to Ireland's independent voice on the global stage.
"His words on that occasion that Ireland should work to 'take our place in the comity of nations and do our part to secure what small nations have always required, the maintenance of peace' remains to this day an important reminder of our nation's role and unique voice on global issues such as disarmament, peacekeeping, human rights and development.
"Liam Cosgrave was committed to serving the people of Ireland with all of his energy, intellect as well as passion. In retirement, he loved to be among the people, be it at State occasions or sporting events and it is fitting that we pay tribute to his significant contribution to Ireland.
"Sabina and I wish to express our deepest sympathy to his children Mary, Liam and Ciarán, to members of the Cosgrave family, and to his wide circle of friends."
Taoiseach Leo Varadkar said Mr Cosgrave "was someone who devoted his life to public service".
In a statement, Mr Varadkar said: "I was deeply saddened to learn of the death of the former Taoiseach and leader of my party, Liam Cosgrave. As Taoiseach and as Leader of Fine Gael I extend my deepest sympathy to his family and friends.
"Liam Cosgrave was someone who devoted his life to public service. A grateful country thanks and honours him for always putting the nation first."
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Former president Mary McAleese said Mr Cosgrave was a man of "long term vision".
She said he was not concerned about his own image or personal legacy.
Speaking on RTÉ’s Today with Sean O'Rourke, Ms McAleese said that she did not get to know him as a person until she ran for election in 1997 and that she was amazed by Mr Cosgrave's willingness to give her his encouragement.
In the Sunningdale Agreement, she said, we saw something of the genius of Liam Cosgrave.
She said he was very wise and gracious, but he also had an incredibly mischievous side.
Speaking on the same programme, former taoiseach and leader of Fine Gael, Enda Kenny, said Mr Cosgrave was always there to offer advice, if you wanted it.
He added that Mr Cosgrave had a very sharp wit.
Mr Kenny said that Mr Cosgrave was someone who cared for his country, who loved his party, but above all loved his family.
He said he would be remembered for his interest in people, his conviction and belief in a politician’s responsibilities, and the way in which he carried out those responsibilities.
Former taoiseach John Bruton said he was privileged to have played a small part in the government Mr Cosgrave led.
Mr Bruton said Mr Cosgrave was "a very, very kind person" and an efficient leader.
He said Mr Cosgrave was a pioneer in politics.
Former taoiseach and former Fianna Fáil leader Bertie Ahern said Mr Cosgrave was a very kind and respectful man.
He described Mr Cosgrave as a "very straight forward guy" and said his best conversations with Mr Cosgrave were in Croke Park.
He added that he always admired the fact that Mr Cosgrave was "tough on law and order".
In a joint statement, former Fine Gael leaders Michael Noonan and Alan Dukes also paid tribute to Mr Cosgrave.
The statement described him as "a great leader" and "a man of great honesty and integrity, devoted to the welfare of the State which his father had helped to found".
I am deeply saddened to hear of the passing of former Taoiseach & Leader of @FineGael Liam Cosgrave. RIP— Frances Fitzgerald (@FitzgeraldFrncs) October 4, 2017
Fianna Fáil leader Micheál Martin also paid tribute to Mr Cosgrave, and described him as a "remarkable tenure in our public life".
In a statement, he said: "It is forty years this year since Liam Cosgrave left frontline politics following the 1977 general election and his relatively low profile since then means that his extraordinary career has often been somewhat overlooked. This is very unfair as, by any standard, his was a quite remarkable tenure in our public life.
"Until today, he was the last taoiseach to be born prior to the foundation of the State. It is also extraordinary to think that a member of the 1948 inter-party government, formed almost 70 years ago, was still with us until today.
Fianna Fáil leader Micheál Martin says Liam Cosgrave demonstrated the importance of commitment to public life and to public service pic.twitter.com/uhpWLpT47u— RTÉ News (@rtenews) October 4, 2017
Mr Martin said that Mr Cosgrave will be remembered as a "fair and principled man who conducted the business of government efficiently".
He said: "His lengthy retirement since he left the Dáil in 1981 has been marked by a quiet dignity. He never sought to re-impose himself in the public consciousness. Instead he returned to family life with his wife Vera who sadly also passed away last year."
Sinn Féin president Gerry Adams also extended his sympathies and condolences to Mr Cosgrave's family.
Mr Adams said: "I want to extend my condolences to the family and friends of former taoiseach Liam Cosgrave on his passing this evening.
"I also want to express my sympathies with the leader of Fine Gael, Taoiseach Leo Varadkar TD and to the Fine Gael party on the death of their former leader."
Labour leader Brendan Howlin said that Mr Cosgrave was "a gentleman to his fingertips, a true patriot".
In a statement, he said "on behalf of the Labour Party, I would like to extend my deepest sympathies to Mary, Liam's sons Liam and Ciarán, and extended family, as well as his many friends, former colleagues and all in the Fine Gael party."
Green party leader Eamon Ryan said that he got to know Mr Cosgrave in recent years.
He said, "He brings you back because of that accent. That slight kind of nasally accent, that could be at home in Plunkett or O'Casey. That kind of Dublin accent which has been replaced by a South California drawl in many instances.
"It was that wit and he had that relic of old decency touched to it. It brought you back to the foundation of our State because of his person history, because of age."
Former Fianna Fáil taoiseach Brian Cowen described Mr Cosgrave as a consummate gentleman who had "an impressive recollection of events and personalities and a repertoire of stories that always amused".
Paying tribute, he added: "His was a life well lived."
Archbishop of Armagh and Primate of All Ireland Eamon Martin described Mr Cosgrave as a "man of strong faith".
He added: "Liam Cosgrave placed great value on the primacy of conscience in his political career and in his private life.
"One of the high points of his life was his attendance at the 1975 canonisation in Rome of the martyred Saint Oliver Plunkett during which he read one of the readings at the Mass."
Archbishop of Dublin Dr Michael Jackson said Mr Cosgrave "combined courage and courtesy with political patience".
He added: "Members of the Church of Ireland community wish to express sadness and sympathy to the family and friends of former Taoiseach Liam Cosgrave.
"He will be remembered for his dedication and service to the Irish people and his contribution structurally to a solid understanding of reconciliation right across Ireland."