Gerry Adams has announced his intention to stand down as president of Sinn Fein in 2018.
The 69-year-old veteran politician - who has been president of Northern Ireland's second-largest party since 1983 - told the party's annual conference in Dublin he would not run in the next Irish parliamentary elections.
Last year Mr Adams confirmed he and the late Martin McGuinness had agreed an exit plan.
Michelle O'Neil replaced Mr McGuinness as leader in the North and it is widely expected Mary Lou McDonald will replace Mr Adams.
He is however expected to seek re-election as president today at the party's Ard Fheis, but will then set out his long term plans.
But in his leader's speech, he told republican faithful it would be the last time he would put himself forward for the role.
Mr Adams's importance to his party should not be underestimated.
He continued: "I want to thank everyone who has welcomed me into their homes and communities and who have made me part of countless campaigns, countless elections and countless negotiations".
He paid special tribute to his wife Collette and son Gearoid.
Many believe Sinn Fein's popularity among voters is hampered by the presence of leaders from Ireland's era of Troubles.
The party will debate over one hundred motions on justice, education and health, including motions on abortion, and one which would give party members a free vote on the issue.
Adams said Sinn Fein would be working towards a unity referendum to be held within the next five years. His widow Bernie attended as tributes were paid to the former IRA commander turned Stormont deputy first minister.