Signed at *Hillsborough Castle on 15 November 1985 by the prime ministers of the United Kingdom and Ireland, Margaret Thatcher and Garrett FitzGerald. The agreement set up a regular inter-governmental conference of ministers and officials. It therefore gave the republic of *Ireland a say, albeit oblique, in the affairs of *Northern Ireland. Widely welcomed by others, it was strenuously opposed in Ulster by many Unionists, particularly those of Ian Paisley's faction.