The Anglo-Irish Agreement was a treaty between the United Kingdom and Ireland which aimed to help bring an end to the Troubles in Northern Ireland. The treaty gave the Irish government an advisory role in Northern Ireland's government while confirming that there would be no change in the constitutional position of Northern Ireland unless a majority of its people agreed to join the Republic. It also set out conditions for the establishment of a devolved consensus government in the region.
The Agreement was signed on 15 November 1985 at Hillsborough Castle, by the British Prime Minister, Margaret Thatcher, and the Irish Taoiseach, Garret FitzGerald.
The agreement established the Anglo-Irish Intergovernmental Conference, made up of officials from the British and Irish governments. This body was concerned with political, legal and security matters in Northern Ireland, as well as "the promotion of cross-border co-operation". It had a consultative role only – no powers to make decisions or change laws were given to it. The Conference would only have power to make proposals "insofar as those matters are not the responsibility of a devolved administration in Northern Ireland". This provision was intended to encourage the unionists (who opposed Irish government involvement in Northern Ireland through the Conference) into power-sharing devolved government. The Maryfield Secretariat was the conference's permanent secretariat, including officials from the Republic's Department of Foreign Affairs, based in the Belfast suburb of Maryfield. The presence of civil servants from the Republic particularly incensed unionists. The Maryfield offices closed in December 1998 after the British–Irish Intergovernmental Conference superseded the Anglo-Irish Intergovernmental Conference.