My friend and former colleague Robert Leeson, who has died aged 85, was a powerful force for change in children's books in the 1970s and 80s, as a critic, campaigner and creator. The author of more than 70 titles, he championed robust storytelling free of the scars of class, gender and race bias that bedevilled conventional children's literature at the time.
Born in Barnton, Cheshire, the youngest of four children, Bob joined his local paper on leaving school before national service took him into the army and to Egypt, where he edited a clandestine Nissen hut newspaper. It was not surprising that, as a communist whose passion was writing, he continued as a journalist, post-army, on the Daily Worker and its successor the Morning Star, for which he served as a broad-minded and knowledgable literary editor, as well as a witty feature writer.
He achieved his ambition of becoming a full-time writer when he was in his 40s. Alongside fascinating studies in trade union history, he crafted an impressive array of adventures for younger audiences, criss-crossing genres and historical periods, from a splendid trilogy set in the late 16th/17th centuries to sci-fi tales and The Third-Class Genie (1975), in which the eponymous hero lives in a beer can and ends up pursued as an illegal immigrant.
Bob's fertile output included five novels inspired by the characters in the BBC TV series Grange Hill, beginning with Grange Hill Rules, OK? (1980). His imaginative creation of different milieus was fed by countless visits he made to schools, aimed at fostering in his youthful listeners the same love of writing and reading that drove him.
As chair of the Writers' Guild's books committee in the early 1980s, he played a vital part in negotiating minimum terms agreements with leading British publishers and in 1985 he was elected chair of the guild itself. Also in 1985, he won the Eleanor Farjeon award for distinguished service to the world of British children's books.
Bob had a marvellous and wicked sense of humour (which he used like a harpoon to prick pomposity) and the densely detailed erudition common among autodidacts. He kept writing until the end, self-publishing regular volumes of poems illustrated by his Norwegian wife, Gunvor, whom he met in Budapest in 1952 and married two years later in Oslo.
He is survived by Gunvor and their two children, Fred and Christine.