John Christopher (pen name of Sam Youd) was born in 1922 in Liverpool. His novels were popular during the 1950s and 1960s, most notably The Death Of Grass. In 1966 he started writing science-fiction for adolescents. The Tripods trilogy, the Prince in Waiting trilogy (also known as the Sword of the Spirits trilogy) and The Lotus Caves are still widely read today.
John Christopher died in February 2012.