He was born at Cwmaman, near Aberdare in one of the South Wales Valleys, the Cynon Valley, in the South Wales Coalfield. His father was a school teacher, his three brothers were coal miners. By the time he attended Cowbridge Grammar School, he was already interested in writing. He went on to the University College of Wales, Aberystwyth and the University of Manchester, Manchester. He was unsuccessful as a journalist and instead earned his living as a supply teacher.
In 1939, he met Gweno Ellis, a teacher, whom he married in 1941. In 1941, he collaborated with artists John Petts and Brenda Chamberlain on the "Caseg broadsheets". Although best known as a poet, his first published work was a volume of short stories, The Last Inspection (1942). In his poem Raider's Dawn Lewis makes a biblical reference to Peter and Paul.
He joined the army in 1940 although he was a pacifist. In 1942 he was sent to India with the South Wales Borderers.
He died in Burma, in the course of the Second World War campaign against the Japanese. He was found shot in the head, after shaving and washing, near the officers' latrines, with his revolver in his hand. He died from the wound six hours later. Despite the suggestion of suicide, an army court of inquiry subsequently concluded that he had tripped and the shooting was an accident.
All Day it has Rained
All day it has rained, and we on the edge of the moors Have sprawled in our bell-tents, moody and dull as boors, Groundsheets and blankets spread on the muddy ground And from the first grey wakening we have found
No refuge from the skirmishing fine rain And the wind that made the canvas heave and flap And the taut wet guy-ropes ravel out and snap, All day the rain has glided, wave and mist and dream, Drenching the gorse and heather, a gossamer stream Too light to stir the acorns that suddenly Snatched from their cups by the wild south-westerly Pattered against the tent and our upturned dreaming faces. And we stretched out, unbuttoning our braces, Smoking a Woodbine, darning dirty socks, Reading the Sunday papers - I saw a fox And mentioned it in the note I scribbled home;
And we talked of girls and dropping bombs on Rome, And thought of the quiet dead and the loud celebrities Exhorting us to slaughter, and the herded refugees; -Yet thought softly, morosely of them, and as indifferently As of ourselves or those whom we For years have loved, and will again Tomorrow maybe love; but now it is the rain Possesses us entirely, the twilight and the rain.
And I can remember nothing dearer or more to my heart Than the children I watched in the woods on Saturday Shaking down burning chestnuts for the schoolyard's merry play Or the shaggy patient dog who followed me By Sheet and Steep and up the wooded scree To the Shoulder o' Mutton where Edward Thomas brooded long On death and beauty - till a bullet stopped his song.
In 1989 his widow published Letters to my Wife.