Plaid Cymru (Welsh Nationalist Party). Plaid Cymru was established in 1925 mainly to campaign for the protection of Welsh language and culture. After the Second World War the organization took on the functions of a political party to tread the parliamentary road to Welsh independence. During the 1960s its policies became more economically motivated, aimed at reducing unemployment, halting the migration of Welsh youth, and replacing declining traditional industries. It had little success until 1966 when it won a by-election at Carmarthen. In the election of February 1974 two seats were gained—Caernarfon and Merioneth. Plaid Cymru exploited the minority position of the Labour government (1974–9) to force discussion on constitutional change. However, the March 1979 devolution referendum was a blow to the party. From a turn-out of 58.3 per cent, only 11.8 per cent voted for a Welsh assembly.

The break-through which Plaid Cymru had been looking for came with the referendum of September 1997, which voted by a narrow majority to establish a National Assembly. At the subsequent election in 1999, the party won 17 of the 60 seats in the Assembly, making substantial inroads into the Labour vote, taking seats at Islwyn, Llanelli, and Rhondda. Disappointing results in the election of 2003 led to the resignation of the party's leader, Ieuan Wyn Jones. In 2005, the party took three seats at Westminster, holding Carmarthen East, Caernarfon, and Meirionydd, but losing Ceredigion to the Liberal Democrats.

Richard A. Smith

Plaid Cymru (Party of Wales) Welsh nationalist political party, founded in 1925 as Plaid Genedlaethol Cymru. A Plaid Cymru representative was first elected to the House of Commons in 1966. It advocates Welsh independence (from the United Kingdom) within the European Union.