He has been described as a man who "made great and courageous efforts"
The Supreme Court has paid tribute to Mr Justice Adrian Hardiman, who died suddenly today.
In a statement, the court said: "The State has lost a colossus of the legal world: a good and true friend has been lost by his colleagues on the Court".
"Mr Justice Hardiman had a most successful career as a barrister, he was a leader at the Bar, was renowned for his extensive practice and great skill, including in cross-examination".
"His profound knowledge of the law, and his fluency in expressing his views, have added immensely to the legal jurisprudence of this State".
"He was a Renaissance man. He was a historian. He spoke and wrote on many topics, including the trial of Robert Emmet, the 1916 Rising, and we were looking forward to his lecture, on Easter Monday, here in the Four Courts, on the 1916 Proclamation".
"His eloquence in conference, his depth of knowledge, his humour, but most of all his friendship, will be sorely missed by each member of the Court", the statement added.
Born in Dublin, he was educated at Belvedere College, University College Dublin - where he graduated in history - and the King's Inns.
He was called to the Bar in 1974, and practised as a barrister for the next 26 years.
He used to write and broadcast regularly on legal and political topics. He was appointed to the Supreme Court in the year 2000.
The Taoiseach Enda Kenny led tributes earlier.
"I was shocked and saddened to hear of the death Adrian Hardiman this morning," Mr Kenny said.
"Adrian had a long and illustrious legal career and was one of the great minds of our time. As well as his enormous contribution to our judicial system, he had a love of our language, a huge interest in history and politics and was also a published writer and broadcaster".
"Most importantly, Adrian was also a much-loved husband and father, and to his wife Yvonne Murphy and children, I extend my sincere condolences and those of my Government and the Irish people", he added.
Chief Justice Susan Denham has said she "received the news with great sadness and shock and her immediate reaction was to be mindful of the needs of his wife and family".
She described Justice Hardiman as "a man who had made great and courageous efforts on behalf of those who sought justice".
"He neither favoured nor feared any interest - and went about his work with great integrity, grit and dedication", she added.
Newstalk Breakfast presenter Ivan Yates earlier paid tribute to Mr Justice Hardiman.
He unsuccessfully stood for Fianna Fáil in the local elections of 1979, and was a founding member of the Progressive Democrats.
The UCD School of Law tweeted to say they were "shocked & saddened" to hear of his sudden death.
And the King's Inns said they mourn his passing with great sadness".
We mourn with great sadness the passing of our Bencher colleague, Supreme Court Judge Adrian Hardiman.— King's Inns (@KingsInns) March 7, 2016
The chairman of The Council of The Bar of Ireland, David Barniville, said that Mr Hardiman was "a colossus at the Bar and on the Supreme Court" and that his sudden and untimely death last night has greatly shocked and saddened the entire legal profession in Ireland.
"It was with great sadness and shock this morning that we learned of the sudden death of Mr Justice Adrian Hardiman".
"Mr Justice Hardiman was a colossus at the Bar and on the Supreme Court and was highly regarded and deeply respected by all who knew him".
"He was arguably the leading advocate of his generation at the Bar and one of Ireland’s finest jurists", Mr Barniville added.
Mr Justice Hardiman was a Bencher of the King's Inns, a Master of the Bench of the Middle Temple, London, and a Member of the Royal Irish Academy.
He is survived by his wife, retired judge and author of the Murphy Report, Yvonne Murphy and his sons - Eoin, Hugh and Daniel.