The Speaker of the Northern Ireland Assembly has confirmed his retirement.
In a letter read out to the assembly, the DUP's William Hay said ill-health had prevented him from making the announcement in person.
Mr Hay, who was elected Speaker following the restoration of devolution in May 2007, has been absent from the chamber since last month when he stepped aside to receive treatment for a heart problem.
He said he would officially retire next Monday to concentrate on his recovery.
The Foyle MLA, who was born in Donegal, had been due to leave the post after being made a member of the House of Lords in August, deciding to sit on the crossbenches.
Sinn Fein's Mitchell McLaughlin, the Assembly's principal deputy speaker, described Mr Hay as a "remarkable servant" of the Stormont institutions.
He said: "I have made arrangements and advised the whips to consider how best to pay tribute to a man who justly deserves that. The most appropriate way to do that is upon reflection of today's announcement."
Politicians are expected to formally pay tribute to the Speaker next week.
William Hay was first elected as a councillor in Londonderry in 1981 and served as mayor in 1993. He played a key role in resolving parading tensions in his Derry constituency before stepping down from the council in 2010.
The veteran politician was first elected to the Northern Ireland Assembly in 1998.
DUP MLA Peter Weir wished him a full and swift recovery.
The SDLP MLA Pat Ramsey said: "I may not have always agreed with his rulings but there can be no doubt that he exercised his office robustly and with fairness.
"His attitude toward, and occasional scolding of, his own party colleagues demonstrates that he approached the difficult role with equality and parity of treatment at the core of all that he did."
In a statement First Minister Peter Robinson described Mr Hay as devoted and diligent.
The DUP leader said: " His qualities of hard work and devotion to his constituents have been reflected in election after election: whether it be to Londonderry council or the Northern Ireland Assembly, people in the Foyle constituency rewarded him with their votes.
"As he ends his career in electoral politics, William can take pride in the fact that he made the city and the surrounding area a better place by the work he undertook on behalf of his constituents.
"As Speaker of the Northern Ireland Assembly, William has shown absolute impartiality and fairness in the chair.
"He always defended the rights of Assembly members to full and fair participation in debates and at all times sought to ensure the tone of debate was measured and respectful: sometimes not an easy task in Stormont."