Published Tuesday, 27 May 2014
Originally from Omagh, Co Tyrone, he was best known for being one of the very few high profile Catholic unionist politicians in Northern Ireland.
However, before his entry into politics, Sir John was a familiar name as a decorated war hero of the Second World War and a leading business figure.
A member of the Irish Guards, he was awarded the prestigious Military Cross for his actions in leading his crew to safety after their tank came under fire from the Germans.
He was promoted to the rank of captain, and after the war left the army to become an RUC inspector.
Sir John also headed the Northern Ireland Housing Executive and was the first chairman of the Northern Ireland Forum for Political Dialogue.
He stood for the Ulster Unionist Party and was elected representative to the Assembly in 1998, representing the North Down constituency. He went on to hold the position of Deputy Speaker of the Assembly.
Sir John received many awards during his lifetime - he was knighted by the Queen in 1998 and also held the title of Deputy Lord Lieutenant of County Down.
In 2007, he was awarded with the French military decoration Croix De Guerre for actions during World War II.
He was an impressive character and Northern Ireland owes him a great debt.
UUP leader Mike Nesbitt
Ulster Unionist Party leader Mike Nesbitt said Sir John was "one of a kind".
He said: "It is rather poignant that on the very day we complete a European Election count to return Northern Ireland's MEPs to Brussels, we should learn of the death of a man who liberated that city 70 years ago.
"Sir John achieved success in a number of fields. He was a war hero, a great public servant and a leading catholic unionist.
"I had the pleasure of working with Sir John when he was Director of the Institute of Directors.
"The last time I was with him was at a branch meeting of the Party in Killyleagh last year.
"He was barely mobile and said he was there simply to support me.
"I was humbled by that gesture and in his death I am inspired to deliver better politics as a tribute to his memory.
"He truly was one of a kind and we are all the poorer for his passing. My deepest sympathies go out to his family and many friends."
Sir Reg Empey, former leader of the UUP, also paid tribute to him saying Northern Ireland would be a poorer place due to his passing.
"It was the variety and breadth of his achievements. He was a decorated soldier and commanded a tank in the Second World War," he said, before discussing his career in business, law enforcement and politics.
"All in all, he made a tremendous contribution to public life and commercial life in Northern Ireland.
"I remember him because of his charm - he was a delightful person, he was well-read, he was courteous.
"His breadth of vision and knowledge made him a very entertaining person to talk to - and to be in his company socially or indeed, politically."
Sir John died at a nursing home in Co Down, close to his family home in Killyleagh.
© UTV News