The authority was a successor to both the administrative county of Monmouthshire (with minor boundary changes)[2] and the county borough of Newport (both authorities which were legally part of England until the Act came into force[3][4] although considered jointly with Wales for certain purposes).

[5][6] Under the Local Government (Wales) Act 1994, the county of Gwent was abolished on 1 April 1996.

"Gwent" is often used as a synonym for the historic county of Monmouthshire – for example the Gwent Family History Society describes itself as "The key to roots in the historic county of Monmouthshire".

[8] The former administrative county was divided into several districts: Blaenau Gwent, Islwyn, Monmouth, Newport and Torfaen.

The successor unitary authorities are Blaenau Gwent, Caerphilly (part of which came from Mid Glamorgan), Monmouthshire (which covers the eastern 60% of the historic county of the same name), Newport and Torfaen.