Completed and published in 1953, Childhood's End sold out its first printing, received good reviews and became Clarke's first successful novel.

In the late 20th century, the United States and the Soviet Union are competing to launch the first spacecraft into orbit when alien spaceships suddenly position themselves above Earth's principal cities.

When the Overlords finally reveal their appearance, they resemble the traditional Christian folk images of demons, with cloven hooves, leathery wings, horns, and barbed tails.

Karellen reveals the Overlords' purpose: they serve the Overmind, a vast cosmic intelligence, as a kind of "bridge species", fostering other races' eventual union with it.

The novel first took shape in July 1946, when Clarke wrote "Guardian Angel", a short story that would eventually become Part I of Childhood's End.

Clarke's portrayal of the Overlords as devils was influenced by John W. Campbell's depiction of the devilish Teff-Hellani species in The Mightiest Machine,[2] first serialized in Astounding Stories in 1934.

After finishing "Guardian Angel", Clarke enrolled at King's College London and served as the chairman of the British Interplanetary Society from 1946 to 1947, and later from 1951 to 1953.

[7] After Clarke's nonfiction science book The Exploration of Space (1951) was successfully received, he began to focus on his writing career.

[9] Clarke proceeded to Tampa Bay, Florida, to go scuba diving with George Grisinger, and on his way there visited his friend Frederick C. Durant – President of the International Astronautical Federation from 1953 to 1956 – and his family in the Washington Metropolitan Area, whilst he continued working on the last chapter.

The short story, "The Man Who Ploughed the Sea", included in the Tales from the White Hart (1957) collection, was influenced by his time in Florida.

While in Key Largo in late May, Clarke met Marilyn Mayfield, and after a romance lasting less than three weeks, they travelled to Manhattan and married at New York City Hall.

In 1990, Clarke added a new foreword and rewrote the first chapter, placing it in the early 21st century, changing the goal from the Moon to Mars, and implying a joint effort rather than a race.

[17] The New York Times published two positive reviews of the book: Basil Davenport compared Clarke to Olaf Stapledon, C. S. Lewis, and H. G. Wells, a "very small group of writers who have used science fiction as the vehicle of philosophic ideas".

[18] William DuBois called the book "a first rate tour de force that is well worth the attention of every thoughtful citizen in this age of anxiety".

He compared Clarke's role as a writer to that of an artist, "a master of sonorous language, a painter of pictures in futuristic colors, a Chesley Bonestell with words".

[21] While acknowledging "inexpressible unpleasant and uncomfortable feelings after reading it", Japanese author Yukio Mishima declared, "I'm not afraid to call it a masterpiece.

"[citation needed] Anthony Boucher and J. Francis McComas were more skeptical, and faulted the novel's "curious imbalance between its large-scale history and a number of episodic small-scale stories".

While praising Clarke's work as "Stapledonian [for] its historic concepts and also for the quality of its prose and thinking", they concluded that Childhood's End was "an awkward and imperfect book".

[22] P. Schuyler Miller said the novel was "all imagination and poetry", but concluded it was "not up to some of Clarke's other writing" due to weakness in its "episodic structure".

[23] Brian W. Aldiss and David Wingrove wrote that Childhood's End rested on "a rather banal philosophical idea", but that Clarke "expressed [it] in simple but aspiring language that vaguely recalls the Psalms [and] combined [it] with a dramatized sense of loss [for] undeniable effect".

[27] Months before his performance at Woodstock in 1969, folk singer and guitarist Richie Havens told Ebony magazine about his appreciation of Clarke's story and expressed his interest in working on a future film adaptation of Childhood's End.

[citation needed] Philip DeGuere, whose credits include the TV series Alias Smith and Jones, developed a script in the late 1970s for Universal, who planned to film it initially as a six-hour mini-series for CBS Television, and later as a two- or three-hour telemovie for ABC.

These contractual difficulties were resolved in 1979 and DeGuere worked with legendary comic book artist Neal Adams on preproduction drawings and other material.