He is arguably Britain’s greatest wartime prime minister, one of the most celebrated orators of the 20th century, and a respected author who won the Nobel Prize for Literature.

But a new essay discovered buried in an American archive, shows that Winston Churchill was also convinced that aliens existed, believing that the universe must contain "living, thinking, creatures".

Most scientists now agree that some form of extra-terrestrial life exists in such a a vast universe, but Churchill was writing more than 50 years before the discovery of the first planet outside of the Solar System.