Blaenau Gwent is a county borough and parliamentary constituency in South Wales. It borders the administrative areas of Monmouthshire and Torfaen to the east, Caerphilly to the west and Powys to the north. Its main towns are Abertillery, Brynmawr, Ebbw Vale and Tredegar.
The borough was formed in 1974 as a local government district. It was a merger of the Monmouthshire urban districts of Abertillery, Ebbw Vale, Nantyglo and Blaina and Tredegar, along with Brynmawr urban district and the parish of Llanelly in Brecknockshire.
It was reconstituted in 1996 as a county borough, excluding Llanelly which instead was transferred to the reconstituted Monmouthshire.
Blaenau Gwent hit the headlines at the 2005 UK General Election when an independent candidate, Peter Law, won the Westminster seat. He had resigned from the Labour Party in protest at the imposition of an all-women candidates' shortlist following the retirement of incumbent MP Llew Smith, and defeated the official Labour candidate, Maggie Jones, by a majority of 9,121 votes. The seat had previously been held by Aneurin Bevan and Michael Foot, and was considered one of Labour's safest. Law died April 25, 2006 and in the by-election, a former supporter of his, Dai Davis won, running as an independent candidate. Peter Law's widow, Trish Law won his former Welsh Assembly seat, also running as an independent candidate.