The seat was created after boundary changes in 1983, as part of an expansion of Northern Ireland's constituencies from 12 to 17, and was predominantly made up from parts of North Down. At its creation the constituency was formed from the local government district of Ards, and the Castlereagh districts of Beechill, Fourwinds, Hillfoot, Lower Braniel, Minnowburn, Moneyreagh, Newtownbreda, and Upper Braniel.
In 1995, the Commission controversially recommended abolishing the constituency and dividing it between North Down and new constituencies of Mid Down, and Castlereagh and Newtownards. This was successfully opposed in local enquiries and from the 1997 general election it was made up of parts of the districts of Ards, Castlereagh and Down.
Despite the name the seat does not currently contain the town of Strangford which is instead a part of South Down.
The constituency has been represented by Unionist candidates since it was formed. There have not been significant votes for parties outside the traditional unionist block, although as the Alliance has saved its deposit in every election.
The main interest in elections has been the contest between the Ulster Unionist Party and the Democratic Unionist Party. Until 2001 the UUP were clearly ahead of the DUP in the Westminster elections, but elections to regional assemblies and local government were much closer. In 2001 the sitting MP John Taylor stood down and the contest to succeed him was fierce. The seat was won by Iris Robinson for the Democratic Unionist Party and the subsequent 2003 assembly election saw the DUP increase their vote further.