The well-known British Science Fiction author John Christopher has died aged 90. His real name was Christopher Samuel Youd, but he wrote under eight pseudonyms, with John Christopher, being the best known. A prolific writer, he was awarded the Guardian Award in 1976 for his children’s novel, The Guardians. His first major success as a writer came with his science fiction novel, The Death of Grass, published in 1956 and republished in 2009. It was adapted into film in 1970, as No Blade of Grass. He began writing science fiction for young adults in 1966, with the Tripods Trilogy, that became a quartet with A Pool of Fire, published in 1988. The Tripods novels were adapted into a television series.