Obituary: O. M. Roberts

O. M. ROBERTS was the last survivor of a crucial event in the history of Welsh nationalism, the burning of buildings at an RAF base near Caernarvon in 1936. His part in it remained shrouded in secrecy for decades.

The attack was intended to register opposition to the construction of an airfield in the heartlands of the Welsh-speaking communities of North Wales. The arsonists intended to galvanise support for the language, which was perceived as being under particular threat.

The site had been earmarked after the original choice, Abbotsbury in Dorset, was turned down because of the famous swannery. The actual perpetrators - Saunders Lewis, then president of Plaid Cymru, the Rev Lewis Valentine, and D.J. Williams, a Fishguard teacher - gave themselves up at the local police station as soon as the deed was done.

Roberts was a member of the back-up team equipped with wire-cutters and petrol, used to douse buildings. It was never part of the carefully executed plan that the "support team" should be detained; they were given ample time to fade away before the matches were struck. Their role remained a secret until, in his eighties, Roberts published Oddeutu'r Tan ("Concerning the Fire"), by which time he had become a pillar of the establishment.

When the three were tried at Caernarvon, the jury failed to reach a verdict. The case was transferred to the Old Bailey, where they again refused to give evidence in English and were each sentenced to nine months' imprisonment. On their return, thousands of supporters turned out in Caernarvon to give them a hero's welcome.

More than half a century later, the contrast between the action of Lewis, Valentine and Williams, and the campaign by Meibion Glyndwr ("Sons of Glendower"), the clandestine firebombers credited with attacking more than 200 holiday homes in the 1980s, who were never caught, is the subject of continuing debate in Wales.

Born at Llanrug, a Welsh-speaking village near Caernarvon, in 1906, Roberts took a science degree at the University of Wales, Bangor. He then taught in schools in the East End of London before returning to teach in Llandudno and Bethesda.

He was one of the original members of Plaid Cymru, founded in 1925, and served as vice-chairman in the late 1940s. In 1952 he entered politics as a member of Conwy Council where he served as mayor before being elected to Caernarvonshire Council. In 1974 it was subsumed into Gwynedd Authority, which he chaired in 1985/86. He retired in 1989.

Although a long-time member of Plaid Cymru, Roberts always contested elections as an Independent - a stance not uncommon in rural Wales. His reason was simple: he said he was not susceptible to the party whip system.

O. M. Roberts's great love for the Welsh language was fulfilled in 1989 when he chaired the National Eisteddfod in the Conwy Valley. He was tireless in his work for the Urdd Gobaith Cymru, the Welsh youth movement which has a pivotal role in sustaining the Welsh language, a tongue spoken by one in five of Wales's three million people.

Owen Morris Roberts, teacher and politician: born Llanrug, Caernarvonshire 28 March 1906; died Caernarvon 25 February 1999.