Plaid Cymru first put a candidate up for election in Wales in the 1929 general election. That one candidate polled 609 votes out of a total of 1,316,912 votes cast in Wales. By the 1979 general election, the support for Plaid Cymru had grown to 132,544 resulting in Plaid Cymru winning two constituencies in Wales.
1929: 609 votes in Wales
1931: 1,136 votes in Wales
1935: 2,534 votes in Wales
1945: 14,321 votes in Wales
1950: 17,580 votes in Wales
1951: 10,920 votes in Wales
1955: 45,119 votes in Wales
1959: 77,571 votes in Wales
1964: 69,507 votes in Wales
1966: 61,071 votes in Wales
1970: 175,016 votes in Wales
1974 (Feb): 171,374 votes in Wales
1974 (Oct): 166,321 votes in Wales
1979: 132,544 votes in Wales
British Elections 1832 to 1979