Relf was born at Prittlewell, Westcliff-on-Sea, Essex, the son of a civil servant.
He began his artistic career as a painter of landscapes, still life and portraits, working mostly in oils.
[3] At this period his work was regularly featured in the annual Royal Academy exhibitions in London,[1] and in 1949 fourteen of his paintings were exhibited at J H Clarke & Co in Chelmsford, including several Essex scenes, still life compositions and two studies of his small son David.
[4] From the late 1940s, Relf forged a new career as a commercial artist, starting with railway posters.
[2] In the early 1950s Relf moved to Great Chart, near Ashford in Kent, where he mainly produced illustrations for children's adventure stories, a mix of paintings in oil for the dust jackets and black and white line drawings for the inside.