Tributes are being paid to Peter Robinson, who has announced he is standing down as Northern Ireland's First Minister.
He will not contest the next elections in East Belfast and will resign as leader of the DUP.
While no successor has been named to the 66-year-old - but Arlene Foster and Nigel Dodds have been identified as front runners.
Mr Robinson (66) has made the announcement ahead of his party's annual conference this weekend.
He took over as first minister from Ian Paisley in 2008, and says he feels now is a good time to go.
The Taoiseach Enda Kenny says that it was an expected announcement.
Foreign Affairs Minister Charlie Flanagan said in a statement: "I was very sad to learn this morning of Peter Robinson’s intention to retire from politics in the near future".
"At the appropriate moment, there will be an opportunity to fully record our appreciation for the positive contribution he has made to politics and society in Northern Ireland over recent times".
"From my own direct experience of working closely with Peter, I wish to acknowledge his leading role in bringing stability to the political institutions in Northern Ireland, which was most recently demonstrated in the ‘Fresh Start’ Agreement of which he was a key architect", he added.
Sinn Féin President Gerry Adams 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".
And Fianna Fáil leader Micheál Martin also wished Mr Robinson well in his upcoming retirement.
"As Minister for Foreign Affairs from 2008 to 2011, I worked closely with Peter, including the negotiations surrounding the devolution of policing and justice to the North".
"I always found him to be a pragmatic and straightforward politician who was serious about moving Northern Ireland forward".
"There is no doubt that he made a significant contribution to the journey that the island of Ireland has been on. We wish him and his family well in his retirement".
The chairman of the DUP, Maurice Morrow, said: "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. That is in no small part due to his efforts and contributions," he added.
Mr Robinson's announcement comes during the same week that a deal was reached between the major parties in Northern Ireland to bring an end to the political crisis at Stormont.
A reduction in the rate of corporation tax was agreed as part of the Stormont House Agreement, which brought to an end the months-long talks over a broad range of issues.
