Dr Martin Mansergh has served as adviser to three Fianna Fail taoisigh in the past 20 years and is regarded, across all parties, as the chief backroom expert on the national question. He played a major role in the negotiation of the IRA ceasefire and the subsequent talks leading to the Belfast Agreement.
Son of the distinguished historian Nicholas Mansergh, he was educated in England, studied for and received a doctorate from Oxford, and moved back to the family farm in Tipperary in the early 1970s.
Dr Mansergh joined the Department of Foreign Affairs as a third secretary in 1974. The former Taoiseach, Mr Haughey, invited him to join the Department of the Taoiseach as a principal officer in late 1980. He served as Fianna Fail's head of research when the party went into opposition.
He has been with Fianna Fail since. It is a tribute to his acknowledged role in Anglo-Irish negotiations that Mr John Bruton invited him to remain as adviser after the fall of Mr Albert Reynolds's government in 1994. He declined the offer.
A member of the Church of Ireland, he serves on the council of Alexandra College in Dublin. He is a trustee of Farahy Church in north Cork and a nominee to the board of Cashel Bolton Library.