In the 1929 general election the party contested its first parliamentary constituency, Caernarvonshire, polling 609 votes, or 1.6% of the vote for that seat.
The party contested few such elections in its early years, partly due to its ambivalence towards Westminster politics.
In September 2008, a senior Plaid assembly member spelled out her party's continuing support for an independent Wales.
The Welsh Minister for Rural Affairs, Elin Jones, began Plaid's annual conference by pledging to uphold the goal of making Wales a European Union member state.
She told the delegates in Aberystwyth that the party would continue its commitment to independence under the coalition with the Welsh Labour Party.
In 1962 Saunders Lewis gave a radio talk entitled Tynged yr Iaith (The fate of the language) in which he predicted the extinction of the Welsh language unless action was taken.
This led to the formation of Cymdeithas yr Iaith Gymraeg (the Welsh Language Society) the same year.