The men who lit a match under an RAF base - and Welsh nationalism

In the early hours of 8 September 1936, three middle-aged academics with no prior history of criminality trudged through a field, armed with petrol cans, to set fire to an RAF bombing school.

This was arguably the event that placed Welsh nationalism on the map, with reportedly 20% of the population coming out in support, one historian said.

Plaid Cymru founders Lewis Valentine, Saunders Lewis and DJ Williams were bitterly opposed to RAF Penrhos being on the Llyn Peninsula - the spiritual route on the North Wales Pilgrims Way.

Now their protest has been recreated in the opera Fflamau Penyberth [Flames of Penyberth] by the world's only Welsh-language company, OPRA Cymru.

For more than 600 years the farmhouse of Penyberth had been used as a form of hostel and mentoring centre for those seeking to expand their knowledge of religion and Welsh history.

Yet, with a single stroke of a pen, it was condemned for demolition, owing to the national need.

Similar protests from the other proposed sites in Dorset and Northumberland had been sympathetically received by the UK government on environmental grounds, but Penyberth's cultural significance was not deemed sufficient to prevent the location of the RAF base there.

Historian Arwel Vittle, who helped transcribe the libretto into Welsh, said the three men met at the National Eisteddfod in 1925 when they, along with other nationalists, formed Plaid Genedlaethol Cymru (the Welsh National Party), the forerunner of today's Plaid Cymru.

"Although Lewis Valentine, DJ Williams and Saunders Lewis were in agreement about the need for home rule, they also felt that there needed to be an awakening of the Welsh language and culture in the general population, before we could hope to take control of our own affairs as a mature nation in our own right."

Vittle explained that it was frustration in the failure of the nationalist party to succeed electorally that had seen Welsh nationalism remain on the fringes of mainstream politics until the 1930s

"In February 1936, and again in May, protests in Pwllheli had attracted upwards of 5,000 people, but there would be no compromise.

"The government cited the minority of counter protesters who came out in favour of the base, arguing the economic benefits of jobs and trade for local businesses in the midst of the Great Depression."

Vittle said that, across Wales, about 500,000 people - roughly 20% of the population at the time - attended rallies and public meetings opposing the plans, but their protests fell on deaf ears.

By September, with construction in the very early stages, the three felt they needed to take direct action before planes and personnel were based there, after which the potential for casualties and damage would be much greater.

"It was very much a symbolic act, not meant to endanger life or property, but to convey the anger of Welsh people," said Vittle.

"Along with four helpers who Valentine, Saunders and Williams refused to name at trial, several small fires were set, burning down a handful of temporary huts.

"No-one was injured and the estimated damage was £3,000, which even in 1930s' prices was negligible in terms of military spending."

Immediately after, the three handed themselves into the nearest police station, admitted their crime and presented a written statement for their motives.

They stood trial in Caernarfon, where a sympathetic jury failed to reach a verdict - with Vittle saying that the foreman even congratulated them in the local pub after the mistrial.

Not content with the outcome, the Crown sought a retrial at the Old Bailey, where they were found guilty and sentenced to nine months imprisonment.

"From the perspective of Valentine, Saunders and Williams, the judicial process couldn't have gone better," said Vittle.

"They'd proved the support of their own community in Caernarfon and then went on to become political prisoners on the enormous stage of the Old Bailey."

Released a fortnight early in August 1937, they returned home to a rapturous crowd of more than 15,000.

The operatic interpretation of the tale has been created by Patrick Young, founder of OPRA Cymru.

Amazingly, for the head of the only Welsh-language company, he is a Welsh learner, grasping the language as he goes along.

"I've had roles in English and Italian opera, but no language lends itself to the art like Welsh.

"It has a rhythm which is helped by the fact that there is no extraneous grammar, you get to the point of the sentence in very clear terms, which makes an extremely powerful libretto."

Founded 18 years ago, OPRA Cymru expanded from "three performers and a keyboard", to major productions of seminal works translated into Welsh.

Fflamau Penyberth begins with Valentine in a Wormwood Scrubs cell - he is struggling from life-long claustrophobia, as well as the effects of nicotine withdrawal from smoking.

Young said: "We see Lewis Valentine struggling with his fundamental beliefs, and the hardships which his incarceration is putting upon him.

"He isn't the most mistreated political prisoner in history, but the scene demonstrates the conflict between his cause and the privations he is enduring... he asks himself, 'was it all worth it'?"

With music composed by Gareth Glyn, the opera recounts the story through flashbacks of the three men's memories, from the 1936 protests, through to catching a bus to Llyn, loading a car with cans of petrol, final preparations in a pub on the evening of 7 September and the eventual blaze.

Vittle suggests it was a propaganda success for the three, but the party failed to build on it.

"RAF Penrhos turned out to be an utter white elephant," he said.

"The unique microclimate of the Llyn Peninsula meant that the mist in the area made it next-to-useless for gun and flight training and it served almost no use in the coastal defence of Liverpool either.

"Meanwhile, whilst Valentine, Saunders and Williams' convictions caused a momentary uplift in Welsh national sentiment while the three were in prison, the movement lost leadership.

"Although they corresponded regularly the three men did not meet up with each other for decades after their release and it would take another 30 years before Plaid Cymru had an elected MP."

Fflamau Penyberth is touring across Wales throughout November and December.