Gwent is a preserved county and a former local government county in south-east Wales. It was formed on 1 April 1974, under the Local Government Act 1972, and was named after the ancient Kingdom of Gwent. The authority was a successor to both the administrative county of Monmouthshire (with minor boundary changes) and the county borough of Newport. Both authorities were explicitly defined as part of Wales by the Act; they had previously been considered jointly with Wales for certain purposes.
Under the Local Government (Wales) Act 1994, Gwent was abolished on 1 April 1996. However, it remains one of the preserved counties of Wales used for the ceremonial purposes of Lieutenancy and High Shrievalty, and its name also survives in various titles, e.g., Gwent Police, Royal Gwent Hospital, Gwent Wildlife Trust, Coleg Gwent college and the Newport Gwent Dragons rugby team. Given the similarity in area, it is sometimes 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".
When it existed, the administrative area was divided into several districts: Blaenau Gwent District, Islwyn District, Monmouth District, Newport District and Torfaen District. The successor unitary authorities are the Blaenau Gwent County Borough, Caerphilly County Borough (part of which came from Mid Glamorgan), Monmouthshire (which covers the eastern 60% of the historic county), City of Newport and Torfaen County Borough.
In 2003 the preserved county of Gwent expanded to cover the whole of Caerphilly County Borough; the Gwent Police area having already been realigned to these boundaries in 1996. In 2007, the population of this enlarged area was estimated as 560,500, making it the most populous of the preserved counties.
- Less the parish of St Mellons and urban districts of Bedwas and Machen, Rhymney and part of Bedwellty and the addition of the parishes of Llanelly and Brynmawr.
- Local Government Act 1972 c. 70, s. 1 New local government areas in England, ss. 12 'In this section "England" does not include the administrative county of Monmouthshire or the county borough of Newport.' & s. 20 New local government areas in Wales, ss. 7 'In this section "Wales" includes the administrative county of Monmouthshire and the county borough of Newport.'
- "Local Government (Wales) Act 1994 c. 19, s. 1(1)". 5 July 1994.
- "Gwent Family History Society". Retrieved 2010-09-11.
- "The Preserved Counties (Amendment to Boundaries) (Wales) Order 2003". Office of Public Sector Information. 2003-04-01. Retrieved 2010-09-11.
- 2007 population estimate, calculated using 2003 borders for Blaenau Gwent, Caerphilly, Monmouthshire, Newport, Torfaen. Source: "Table 10: Mid-2006 to Mid-2007 Population Estimates, Components of population change for local authorities in the United Kingdom". Office for National Statistics. Retrieved 2010-09-11.