The Anglo-Irish Agreement was a 1985 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 citizens agreed to join the state of Ireland. It also set out conditions for the establishment of a devolved consensus government in the region. The most powerful pressure for the Agreement came from the United States, where the Irish American lobby had a strong influence. Led by the Speaker of the House of Representatives, Tip O'Neill, and Senators Edward Kennedy and Daniel Moynihan, the Irish lobby regularly denounced what they considered British colonialism and human rights violations in Northern Ireland. Reagan, who was also Irish American and visited Ireland in June 1984, increasingly encouraged British Prime Minister Margaret Thatcher to make progress on Anglo-Irish talks. By January 1985, Thatcher was persuaded that progress must be made on the issue. Her primary aim was security but realised that for help in this area she would need to concede in other areas, such as grievances over policing and the courts. The Agreement was signed on 15 November 1985, at Hillsborough Castle, by the Thatcher and the Irish Prime Minister Garret FitzGerald and was also known by the alternative title "Hillsborough agreement".
The Agreement failed to bring an immediate end to political violence in Northern Ireland; neither did it reconcile the two communities. The Agreement was widely rejected by unionists because it gave the Irish government a role in the governance of Northern Ireland for the first time ever, and because they had been excluded from the agreement negotiations. The agreement was rejected by republicans because it confirmed Northern Ireland's status as a part of the UK. The devolved power-sharing government envisaged by the Agreement would not become a reality for many years, and then in quite a different form. However, it did improve co-operation between the British and Irish governments, which was key to the creation of the Good Friday Agreement thirteen years later.
Mary Robinson, who subsequently became President of Ireland, resigned from the Irish Labour Party because she believed that the Agreement could not secure peace and stability within Northern Ireland and because she disagreed with how the unionist community had been excluded from negotiations.
Material in this section consists of reports, correspondence and other material relating to the drafting and signing of the agreement, reactions to it, and the fallout of MR's resignation from the Labour party because if it.