, ), often shortened to Plaid, originated in 1925 after a meeting held at that year's National Eisteddfod in Pwllheli, Caernarfonshire (now Gwynedd).John Davies, A History of Wales, Penguin, 1994, , Page 547 Representatives from two Welsh nationalist groups founded the previous year, Byddin Ymreolwyr Cymru ("Army of Welsh Home Rulers") and Y Mudiad Cymreig ("The Welsh Movement"), agreed to meet and discuss the need for a "Welsh party".Davies, op cit, Page 547 The party was founded as Plaid Genedlaethol Cymru, the National Party of Wales, and attracted members from the left, right and centre of the political spectrum, including both monarchists and republicans. Its principal aims include the promotion of the Welsh language and the political independence of the Welsh nation.

Although Saunders Lewis is regarded as the founder of Plaid Cymru, the historian John Davies argues that the ideas of the left-wing activist D. J. Davies, which were adopted by the party's president Gwynfor Evans after the Second World War, were more influential in shaping its ideology in the long term.John Davies, Wales and America According to the historian John Davies, D. J. Davies was an "equally significant figure" as was Lewis in the history of Welsh nationalism, but it was Lewis's "brilliance and charismatic appeal" which was firmly associated with Plaid in the 1930s.Why Not a Welsh Royal Family? by Siôn T. Jobbins, January 2008, Cambria magazineJohn Davies, A History of Wales, Pages 591, 592

After initial success as an educational pressure group, the events surrounding Tân yn Llŷn (Fire in Llŷn) in the 1930s led to the party adopting a pacifist political doctrine. Protests against the flooding of Capel Celyn in the 1950s further helped define its politics. These early events were followed by Evans's election to Parliament as the party's first Member of Parliament (MP) in 1966, the successful campaigning for the Welsh Language Act of 1967 and Evans going on hunger strike for a dedicated Welsh-language television channel in 1981.

Plaid Cymru is currently the largest political party in Wales, with 43 out of 96 seats in the Senedd. From 2007 to 2011, it was the junior partner in the One Wales coalition government, with Welsh Labour. Plaid held one of the four Welsh seats in the European Parliament, holds four of the 40 Welsh seats in the UK Parliament, and it has 203 of 1,253 principal local authority councillors. According to accounts filed with the Electoral Commission for the year 2018, the party had an income of around £690,000 and an expenditure of about £730,000.

Background

There had been discussions about the need for a "Welsh party" since the 19th century.Davies, op cit, pages 415, 454 With the generation or so before 1922 there "had been a marked growth in the constitutional recognition of the Welsh nation", wrote historian Dr John Davies.Davies, op cit, Page 544 A Welsh national consciousness re-emerged during the 19th century; leading to the establishment of the National Eisteddfod in 1861, the University of Wales (Prifysgol Cymru) in 1893, and the National Library of Wales (Llyfrgell Genedlaethol Cymru) in 1911, and by 1915 the Welsh Guards (Gwarchodlu Cymreig) was formed to include Wales in the UK national components of the Foot Guards. By 1924 there were people in Wales "eager to make their nationality the focus of Welsh politics".

Following the 18th century Methodist Revival and continued growth in a distinctive Welsh political consciousness, the Liberal government under Prime Minister William Gladstone (after winning all but 4 Welsh Parliamentary seats in the 1880 election) passed the Sunday Closing (Wales) Act 1881 closing all public houses in Wales on Sundays. It was the first Act since the annexation of Wales by the Laws in Wales Act 1535 and 1542 which applied uniquely to Wales.John Davies, A History of Wales, 1993,

In 1886 the Cymru Fydd movement was founded by influential Welsh figures and politicians, and leter led by David Lloyd George (later the only Welsh Prime Minister of the UK). The movement advocated support for Welsh cultural nationalism as well as Welsh self-government. The movement collapsed in 1896. Plaid Cymru leader and Deputy First Minister Ieuan Wyn Jones said of Cymru Fydd "the ideology and influence of Cymru Fydd helped crystallise the early philosophy of Plaid Cymru, and created the space for a new party to develop".

Following the 1904-1905 Welsh Revival and influence in George's ministry, the Church in Wales was disestablished from the Church of England in 1914, coming into effect in 1920.S. H. Steinberg, ed., A New Dictionary of British History (London 1963)

Support for home rule for Wales and Scotland amongst most political parties was strongest in 1918 following the independence of other European countries after the First World War, and the Easter Rising in Ireland, wrote Dr Davies.Davies, op cit, Page 523 However after George's premiership in the general elections of 1922, 1923, and 1924 "Wales as a political issue was increasingly eliminated from the [national agenda]". By August 1925 unemployment in Wales had risen to 28.5%, in contrast to the economic boom in the early 1920s. For Wales, the long depression began in 1925.

Foundation 1925

It was in this climate that the Welsh Home Rulers group and the Welsh Movement met. Both organisations sent a delegation of three to the meeting, with H. R. Jones heading the Welsh Home Rulers group and Saunders Lewis heading The Welsh Movement. They were joined by Lewis Valentine, D.J. Williams, and Ambrose Bebb, among others. The principal aim of the party was to foster a Welsh-speaking Wales.Davies, op cit, page 548 To this end it was agreed that party business be conducted in Welsh, and that members sever all links with other British parties. Lewis insisted on these principles before he would agree to the Pwllheli conference.

According to the 1911 census, out of a total population of Wales of just under 2.5 million, 43.5% spoke Welsh as a primary language.BBCWales History language map 1911 extracted 12-03-07 This was a decrease from the 1891 census with 54.4% speaking Welsh out of a population of 1.5 million.

In these circumstances Lewis condemned "'Welsh nationalism' as it had hitherto existed, a nationalism characterised by inter-party conferences, an obsession with Westminster and a willingness to accept a subservient position for the Welsh language", wrote Dr Davies. It may be because of these strict positions that the party failed to attract politicians of experience in its early years. However, the party's members believed its founding was an achievement in itself; "merely by existing, the party was a declaration of the distinctiveness of Wales", wrote Dr Davies.

In these early years Plaid Genedlaethol Cymru published a monthly paper called Y Ddraig Goch (the Red Dragon, the national symbol of Wales) and held an annual summer school.

H. R. Jones, the party's full-time secretary, established a few party branches, while Valentine served as party president between 1925 and 1926. In the UK General Election of 1929, Valentine stood for Caernarfon and polled 609 votes. Later they became known as 'the Gallant Six Hundred' when Dafydd Iwan immortalised them in song.Plaid Cymru: Who We Are

By 1932 the aims of self government and Welsh representation at the League of Nations had been added to that of preserving Welsh language and culture. However, this move, and the party's early attempts to develop an economic critique, did not lead to the broadening of its appeal beyond that of an intellectual and socially conservative Welsh-language pressure group.McAllister, L, Plaid Cymru: The Emergence of a Political Party, (2001), Seren "The tentative moves towards elaborating and broadening Plaid's policy portfolio did not allow it to shake off its early identity as a language movement or a cultural pressure group." See also Butt-Phillip, A, The Welsh Question, (1975), University of Wales Press. "It is clear that the Welsh Nationalist Party was at the outset essentially intellectual and moral in outlook and socially conservative.

The Lewis Doctrine 1926–1939

During the inter-war years, Plaid Genedlaethol Cymru was most successful as a social and educational pressure group rather than as a political party.Davies, op cit, page 591 For Saunders Lewis, party president 1926–1939, "the chief aim of the party [is] to 'take away from the Welsh their sense of inferiority... to remove from our beloved country the mark and shame of conquest.'" Lewis sought to cast Welshness into a new context, wrote Dr Davies.

Lewis wished to demonstrate how Welsh heritage was linked as one of the "founders of European civilisation". Lewis, a self-described "strong monarchist", wrote, "Civilisation is more than an abstraction. It must have a local habitation and name. Here its name is Wales." Additionally, Lewis strove for the stability and well-being of Welsh-speaking communities, decried both capitalism and socialism and promoted what he called : a policy of "distributing property among the masses".

Broadcasting campaigns and 1931 Census

With the advent of broadcasting in Wales, Plaid Genedlaethol Cymru protested the lack of Welsh-language programmes in Wales and launched a campaign to withhold licence fees. Pressure was successful, and by the mid-1930s more Welsh-language programming was broadcast, with the formal establishment of a Welsh regional broadcasting channel by 1937.Davies, op cit, page 590

According to the 1931 census, out of a population of just over 2.5 million, the percentage of Welsh speakers in Wales had dropped to 36.8%, with Ynys Môn recording the highest concentration of speakers at 87.4%, followed by Ceredigion (Cardiganshire) at 87.1%, Merionethshire (Sir Meirionnydd) at 86.1%, and Carmarthen at 82.3%. Caernarfonshire listed 79.2%. Radnorshire and Monmouthshire ranked lowest with a concentration of Welsh speakers of less than 6% of the population.

Tân yn Llŷn 1936

In 1936, the British government settled on establishing an airfield known as RAF Penrhos at Penyberth on the Llŷn peninsula, now in Gwynedd. The airfield would also be host to a bombing school, which led to widespread nationalist protests in Wales. The events surrounding the protest, known as ('Fire in Llŷn'), helped define Plaid Genedlaethol Cymru.Davies, op. cit., page 593 The government settled on Llŷn as the site for the new airfield and bombing school after proposals for similar locations in Northumberland and Dorset were met with protests.

The Prime Minister, Stanley Baldwin, refused to hear the case against the planned site, despite a deputation representing 500,000 Welsh protesters. Public opinion in Wales was summed by Lewis when he claimed that the government was intent upon turning one of the "essential homes of Welsh culture, idiom, and literature" into a place for promoting what he viewed as a barbaric method of warfare. Construction of the bombing school building began exactly 400 years after the first of the Laws in Wales Acts 1535–1542 were passed.

On 8 September 1936 the bombing school building was set on fire and in the investigations which followed Lewis, Lewis Valentine and D. J. Williams claimed responsibility. The trial at Caernarfon failed to agree on a verdict and the case was sent to the Old Bailey in London. The three men were sentenced to nine months' imprisonment in WorHM Prison Wormwood Scrubs, and on their release they were greeted as heroes by a crowd of 15,000 people at a pavilion in Caernarfon.