The area of the constituency was similar to that of the
county of Ceredigion.
1999 to 2007 The constituency was created for the
first election to the Assembly, in 1999, with the name and boundaries of the
Ceredigion Westminster constituency. It was a
Dyfed constituency, one of five constituencies that covered, and entirely within, the
preserved county of
Dyfed. The other four Dyfed constituencies were
Carmarthen East and Dinefwr,
Carmarthen West and South Pembrokeshire,
Llanelli and
Preseli Pembrokeshire. They are all within the Mid and West Wales electoral region. The region consisted of the eight constituencies of
Brecon and Radnorshire, Carmarthen East and Dinefwr, Carmarthen West and South Pembrokeshire, Ceredigion, Llanelli,
Meirionnydd Nant Conwy,
Montgomeryshire and Preseli Pembrokeshire.
From 2007 Boundaries changed for the
2007 Assembly election. Ceredigion remained one of five Dyfed constituencies and one of eight constituencies in the Mid and West Wales region. However, boundaries within Dyfed changed, to realign them with local government
ward boundaries and to reduce disparities in the sizes of constituency electorates, and the boundaries of the region changed, to align them with the boundaries of preserved counties. The other four Dyfed constituencies were, again,
Carmarthen West and South Pembrokeshire,
Carmarthen East and Dinefwr,
Llanelli and
Preseli Pembrokeshire. They were all within the Mid and West Wales electoral region. The region consisted of the constituencies of
Brecon and Radnorshire, Carmarthen East and Dinefwr, Carmarthen West and South Pembrokeshire, Ceredigion,
Dwyfor Meirionnydd, Llanelli,
Montgomeryshire and Preseli Pembrokeshire. For Westminster purposes, the same new constituency boundaries became effective for the
2010 United Kingdom general election. ==Voting==