William Glyn Protheroe was born in Swansea on 3 July 1906, the son of William James Protheroe, a shipping clerk, and his wife Jennifer Ann. He studied art under Walter Fuller, and moved to London in the late 1920s where he became a professional cartoonist and press artist. He drew for newspapers including the Sports Post, Sporting News, The Journal and The Leader. In the 1940s he drew for comics published by small publishers, including Gerald Swan (War Comics, Topical Funnies, Cute Fun, New Funnies, Slick Fun, Thrill Comics), A. Soloway (Comic Capers, All Star, Comic Adventures) and Amex (Merry Comics, Midget Comics, Bantam Comics, Mighty Comics, Monster Comics). He signed his work "Glynne" or "Protheroe". He died in Swansea in the third quarter of 1970.
- Alan Clark, Dictionary of British Comic Artists, Writers and Editors, The British Library, 1998, pp. 138-139