Sinn Fein president Gerry Adams was among the first to wish Peter Robinson well in retirement after the Northern Ireland First Minister and DUP leader announced he would be stepping down.
Once implacable foes, the two were central to the landmark deal that saw a previously unthinkable coalition of Sinn Fein and the Democratic Unionists assume the reins of power at Stormont in 2006.
“Good luck 2 Peter Robinson,” Mr Adams tweeted.
Later in a statement, he said: “I wish to extend thanks and best wishes to Peter Robinson and his family and good luck for the future.
“Sinn Féin and the DUP worked closely in recent months through a difficult negotiation to achieve Tuesday’s Stormont House Agreement.
“Sinn Féin will continue to work with the DUP and Peter’s successor and with the other political parties as part of the effort to deliver on the recent agreement and to resolve outstanding issues from other agreements.”
Former Northern Ireland secretary Peter Hain, who was recently made a peer, hailed Mr Robinson’s contribution to the peace process.
“If Ian Paisley was the unionist pilot of the peace process then Peter Robinson was the unionist navigator, an indispensable part of the project that has established self-government and a permanent settlement between bitter old enemies,” said the former Labour minister.
“He will stand tall because of that and because of his leadership as First Minister.”
DUP party chairman Lord Morrow paid tribute to Mr Robinson.
“Peter Robinson was a founding member of our party,” he said. “He has devoted his life to the cause of the advancement of unionism in Northern Ireland.
“As deputy leader and director of elections he was the tactician behind all of the major advances made by the DUP over the course of the last 15 years.
“As party leader and First Minister of Northern Ireland he has led our party and our country through some of the most delicate and difficult phases of the political process.
“There were times when lesser men would have given up and simply walked away, but Peter endured and has worked hard for the people of Northern Ireland.
“His contribution to Ulster society has been immense. Northern Ireland is a better place today than it was when he assumed the office of First Minister.”
Tributes were also paid in the House of Commons.
Bob Stewart, Tory MP for Beckenham, said: “May I add my thanks to Peter Robinson.
“I met him first in 1970 when he was an aspiring politician and I was aspiring to be a halfway decent infantry officer.
“I liked him then. He is honest, straight, he knows how to talk to soldiers and he is in no small part responsible for the decent situation we now have in Northern Ireland.
“I thank him with all my colleagues for what he has done in his work.”
Northern Ireland Secretary Theresa Villiers said: “Peter has done a huge amount of work for the good of Northern Ireland.
“He has achieved many things in his long career in public life.
“Northern Ireland is the better place for his input into public life and politics there over around four decades.”
Also read: Peter Robinson: Tributes paid to DUP leader