His best-known academic work is a reference series, Written for Children: An Outline of English Children's Literature (1965),[1] the definitive work of its time on the subject.
[4] His popular works include Gumble's Yard, his debut novel published in 1961; Widdershins Crescent (1965); and The Intruder (1969), which won the 1971 Edgar Award for Best Juvenile Mystery from the Mystery Writers of America.
In Britain, The Intruder was adapted as a children's TV series starring Milton Johns as the stranger.
Also in Britain, Noah's Castle was filmed by Southern Television, narrated by character Barry Mortimer (Simon Gipps-Kent), and transmitted in seven 25-minute episodes in 1980.
He had had a relationship with Jill Paton Walsh from the early 1970s, but they were only married after the death of her first husband in 2004.