DJ Taylor: Dai Rhys-Davies's professional Welshness is founded less on linguistic oddity than enraptured cultural affiliation

In Dai Rhys-Davies's defence, it cannot be said that his national origins are borne into the room on a plate. The lilting, sing-song voice that he brought with him to London 20 years ago has been toned down a bit now; it is only rarely that he addresses one of his convives as "boyo" or urges him to "look you here".

With his receding, reddish hair and spindly frame, no one could say that he looked Welsh. On the other hand, it is impossible to spend more than five minutes in his company without realising that he comes from Wales, and that when God created the world, Wales was the part in which he set about his work with the greatest enthusiasm.

No, Dai's Welshness is founded less on linguistic oddity than enraptured cultural affiliation, manifesting itself in a steely determination to separate Cambrian wheat from Anglian chaff. The presence of the sports section of a Sunday newspaper is, for Dai, an opportunity to remark that there never was a rugby club like Llanelli, and there never was a football team like Swansea City. The prospect of a general election is a valuable reminder that politics began with Lloyd George and ended with Neil Kinnock, while offering valuable supporting roles for Aneurin Bevan and a turncoat's cameo for the late Lord Jenkins ("a traitor", according to Dai, who "forgot where he came from").

And, once the merits of Dylan Thomas, Max Boyce, Tom Jones, How Green Was My Valley and the Manic Street Preachers have been loudly asseverated, and leeks introduced to any casserole then cooking, there is the pleasant task of identifying fellow nationals not generally known to be Welsh. To inform his listeners that, for example, Stephen Fry spent part of his childhood near Pontypool, or that Dame Judi Dench was christened Angharad is Dai's delight, even if these revelations are sometimes not immediately verifiable.

A genial, talkative man, never shy of the apt geographical comparison ("It's all very fine," he will say, if taken to a Lakeland beauty spot, "but you should see the Wye Valley at this time of year"), he is, curiously enough, discomfited only in the company of other Welshmen. It was one of these, a man from Rhyl, who, addressing him in Welsh and getting no reply, suggested that, in actual fact, Dai was born somewhere in Herefordshire and that the name on his birth certificate is Kevin.