1950s and 1960s

Its first two decades saw MK grow from a small band of committed enthusiasts, into a movement supported by thousands.

Helena Charles (St Day) led the party for the first four years and was also the first person to put MK policies to the electorate, winning a seat on Redruth-Camborne Urban District Council in 1953, fighting under the slogan 'A Square Deal for the Cornish.' She was succeeded as Chairman by Major Cecil Beer in the late 1950s.

Trade unionist Robert Dunstone (Truro) led the party throughout much of the 1960s, before Len Truran (Redruth) took the helm later in the decade. Any list of initiatives taken by Mebyon Kernow in these early years would be very long indeed. Well known political campaigns include those for a Cornish University, a Cornish Industrial Board or Development Agency, opposition to London Overspill, support for traditional Cornish industries, opposition to railway closures and help for Heligoland Freisans who wished to return to their land which was being used as a bombing range by the British government in the mid 1950s.

Mebyon Kernow prepared numerous reports on important policy areas, including Cornish University (30 years before the Lib Dem equivalent), integrated transport system, economic development, education, fishing, mining, broadcasting and local government reform.

The party was also instrumental in promoting Cornwall's distinctive identity, with many party members to the forefront of the Cornish Language revival. MK members worked to promote the use of the Cornish Flag, to support Cornish sports like wrestling and to commemorate Cornish figures of the past. In 1966. MK erected the memorial to An Gof and Flamank in St Keverne where annual commemorations have been held ever since.

At this early stage in its development, Mebyon Kernow was essentially a pressure group and continued as such into the 1970s. This allowed members of other political parties to also hold membership of MK. Such members included Tory MP David Mudd and Liberal MPs Peter Bessel and John Pardoe.

Mebyon Kernow members also starting contesting elections as official party candidates in the mid 1960s - winning seats in Padstow, Penryn, Penzance, the Redruth-Camborne area and Liskeard. In 1967, Mebyon Kernow won its first ever seat on Cornwall County Council at St Day and Lanner - after running a successful campaign against London Overspill.