In 1992, Ceredigion provided one of the largest swings in any constituency in the United Kingdom, as Cynog Dafis - on a joint Plaid Cymru/Green ticket - jumped from fourth to first place to beat the incumbent Liberals.
Mr Dafis consolidated his position significantly in 1997, securing over 40% of the vote.
He resigned from the Commons in January 2000 to concentrate on his work as a regional member of the National Assembly.
Plaid's Simon Thomas won the by-election comfortably, despite a minor revival in the Liberal Democrat vote.
This is a large rural seat - geographically the fourth largest in Wales.
Its main industries are agriculture and food processing, although it is also very dependent on education, and has a disproportionately high number of self-employed workers at about 30%.
Tourism is also increasingly important to the local economy.
The three main centres of population are the market town of Cardigan, and the university towns of Aberystwyth and Lampeter, which between them, have over 8,500 students.
Aberystwyth is also home to the National Library of Wales.
More than half of the constituency's population are Welsh speakers.