National Assembly for Wales constituencies and electoral regions

National Assembly for Wales constituencies and electoral regions were first used for the 1999 elections. New boundaries came into use for the 2007 elections. The total numbers of constituencies and regions (40 constituencies and five regions) remained the same.

The constituencies of the National Assembly for Wales (or Welsh Assembly) (Welsh: Cynulliad Cenedlaethol Cymru) were created with the boundaries of the Welsh constituencies of the House of Commons of the Parliament of the United Kingdom (Westminster), as they were in 1999. The new boundaries were also used for the 2010 United Kingdom general election. Therefore, between the 2007 Assembly election and the 2010 United Kingdom general election, the two sets of constituencies, Assembly and Westminster, had differing boundaries.

Three constituency names, Conwy, Caernarfon, and Meirionydd Nant Conwy, have become historic, and the new boundaries define three constituencies with new names: Arfon, Dwyfor Meirionnydd, and Aberconwy. Generally, the new boundaries define each constituency taking account local government ward boundaries, and define constituencies close to equal in terms of the sizes of their electorates.

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