Clarke's idea for the book began with his short story "Guardian Angel" (published in "New Worlds" #8, winter 1950), which he expanded into a novel in 1952, incorporating it as the first part of the book, "Earth and the Overlords". Completed and published in 1953, "Childhood's End" sold out its first printing, received good reviews and became Clarke's first successful novel. The book is often regarded by both readers and critics as Clarke's best novel and is described as "a classic of alien literature". Along with "The Songs of Distant Earth" (1986), Clarke considered "Childhood's End" to be one of his favourites of his own novels. The novel was nominated for the Retro Hugo Award for Best Novel in 2004.