On 12 October 1984 the Provisional Irish Republican Army (IRA) attempted to assassinate members of the British government, including the prime minister, Margaret Thatcher, at the Grand Hotel in Brighton, England. Five people were killed, including the Conservative MP Sir Anthony Berry; more than thirty people were injured. Thatcher was uninjured. The bombing was a key moment in the Troubles, the conflict in Northern Ireland between unionists and republicans over the constitutional position of Northern Ireland, which took place between the late 1960s and 1998. The IRA decided to assassinate Thatcher during the 1981 Irish hunger strike. Her stance against the return of Special Category Status to republican prisoners-the status that meant they were treated as political prisoners, rather than as criminals-meant the strike was not quickly settled, and ten prisoners died. After two years of planning, including reconnoitering the 1982 and 1983 Conservative Party Conferences, a long-delay time bomb was planted in the hotel by the IRA member Patrick Magee over three weeks before the 1984 conference. The IRA knew the hotel would be occupied by Thatcher and many of her cabinet. The bomb exploded at 2:54 am when most guests were in bed. The force of the explosion was upwards and broke through the roof, dislodging one of the hotel's chimney stacks, which weighed five long tons (5.1 t). This crashed through several floors, killing or injuring many of the occupants. Thatcher decided to continue the conference as normal, and was given a standing ovation by delegates as she entered the stage just six and a half hours after the explosion. The investigation took eight months. A partial palm print was found on the room registration card from when Magee checked in and police surveillance on IRA members led them to him. In 1986 he was tried, convicted, and sent to prison for eight concurrent life sentences, with the recommendation that he serve at least thirty-five years before being considered for parole, but was released under license in June 1999 as part of the Good Friday Agreement. Negotiations between the British and Irish governments that had begun in 1980 continued despite the bombing, although the pace of the talks was slowed to ensure it did not appear that the British government was conceding to pressure because of the bomb. They resulted in the 1985 Anglo-Irish Agreement, which gave the Irish government an advisory role in Northern Ireland's government.