David James Jones (18 May 1899 – 24 December 1968), commonly known by his bardic name Gwenallt, was a Welsh poet, critic, and scholar, and one of the most important figures of 20th-century Welsh-language literature.
Consequently he was imprisoned, initially in Wormwood Scrubs and then in Princetown Work Centre in the former Dartmoor Prison until 1919, which he wrote about in his 1934 novel Plasau'r Brenin('The King's Mansions').
In 1919 he enrolled at University College Wales, Aberystwyth, where he met the writer Idwal Jones, whose biography he had published in 1958.
Jones' father was killed by molten metal in Pontardawe Tinplate Works, which had a deep effect on him.
In 1926 the poem, Y Mynach, won Jones the Chair at the National Eisteddfod of Wales which was held in Swansea.