Castlereagh (Irish An Caisleán Riabhach) was one of the 26 Northern Ireland Districts that existed from 1973 to 2015. The District, whose territory was in the traditional County Down, was established in 1973 and had the status of a Borough. Castlereagh comprised the southeastern suburbs of Belfast. Significant places were Carryduff and Dundonald. In the 23-member district council, the Democratic Unionist Party dominated that could win in the elections of 2005 13 seats. They also provided the mayor with Joanne Bunting. Since 2000 was Castlereagh partners district of Kent in the State of Washington. Castlereagh is not to be confused with the town of Castlerea in the Republic of Ireland. 1 April 2015, Castlereagh went on in the new District Lisburn and Castlereagh, where Minnowburn, Belvoir, parts of Ballyhanwood, Cregagh, Downshire, Galwally, Glencregagh, Hill Foot, Lisnasharragh, Lower Braniel, Merok, Tully Carnet, Upper Braniel and Wynchurch the District Belfast were slammed shut.