Born Cynog Glyndwr Davies at Treboeth in Swansea, Glamorganshire, Wales, he was initially a school teacher and researcher before entering politics.

[3] He completed his secondary education in 1956, leaving grammar school with three A-levels in English, Welsh and history.

Dafis was a Member of Parliament for Ceredigion from 1992 until 2000, having been supported by a coalition of local Plaid Cymru and Green Party activists, the latter of which had worked with him on a number of environmental initiatives.

[15] Between 1992 and 1997 Dafis sat in Parliament as an official Plaid Cymru and Green Party MP, having been elected on a joint ticket.

[17] During this eight-year period as an MP, Dafis voted for homosexual law reform, against greater autonomy for schools, and for removing hereditary peers from the House of Lords.

[22] His controversial comments prompted Cymdeithas yr Iaith Gymraeg to join a chorus calling for his resignation as the Assembly's presiding officer.

[22] In 2002, Dafis announced he would step down from the Assembly at the 2003 elections, despite party leader Ieuan Wyn Jones having asked him not to do so.