David John Moore Cornwell (19 October 1931 – 12 December 2020), better known by his pen name John le Carré (), was a British author, best known for his espionage novels. During the 1950s and 1960s, he worked for both the Security Service (MI5) and the Secret Intelligence Service (MI6). His third novel, The Spy Who Came in from the Cold (1963), became an international best-seller and remains one of his best-known works. According to his son Nicholas, le Carré took Irish citizenship shortly before his death.