Sir William Russell Flint was born in Edinburgh, Scotland, the eldest son of Francis Wighton Flint, commercial artist, and his wife, Jane Purves. He was educated at Daniel Stewart's College and at the age of fourteen was apprenticed for six years as a lithographic artist to a firm of printers. In the evenings, he studied at the Royal Institution School of Art. In 1900, he moved to London to take up a post as illustrator to medical publications. After eighteen months, he moved to a part-time job with Dickinson's, the paper makers, spending half the week studying at Heatherley's. From 1903 to 1907, he was a staff artist on the Illustrated London News. Flint exhibited regularly from 1905 in the water-colour section of the Royal Academy. But he painted also in oils, and was elected to the Royal Institute of Oil Painters in 1910. Around this time, he became a freelance artist, graduating from the illustration of magazine stories to books. In 1917, he became a full member of the Royal Society of Painters in Water-Colours, over which he was to preside in 1936-56. He was elected ARA in 1924 and RA in 1933.
   Flint illustrated Malory's le Morte in 1911 (a four-volume edition bound in vellum which now sells for about 1000 GBP). The illustrations won Flint a silver medal at the Paris Salon in 1913. A two volume edition of Malory's le Morte was re-published in 1920.  Flint illustrated many other books including The Canterbury Tales (1913), The Odyssey (1924) and The Imitation of Christ (1908).