 Letters patent continuing the city status of the county borough were granted on 1 April 1974.The district was therefore styled the City of Cardiff, governed by Cardiff City Council.The district was formed by the Local Government Act 1972, from the county borough of Cardiff, the parishes of Lisvane, Llanedeyrn, Radyr, St. Fagans and Tongwynlais from the former Cardiff Rural district in the administrative county of Glamorgan and the parish of St Mellons from the Magor and St Mellons Rural District in the administrative county of Monmouthshire.