Armagh

... is known as the ecclesiastical capital of Ireland, being the seats of both Primates of All Ireland (Roman Catholic and Church of Ireland - the latter being the Irish province of the Anglican Communion).

Just in case you were wondering, Armagh is in Northern Ireland; it's the county town of the county to which it gives its name. In the 2011 census it had a population of 14,749, making it the least–populated city in Northern Ireland and the fourth smallest in the United Kingdom.

Armagh is historically considered a city, by virtue of its ecclesiastical status as detailed above. It lost its city corporation by Act of Parliament in 1840; city status was officially granted in 1994, in belated celebration of the 40th anniversary of the Queen's accession.