The spy film genre began in the silent era, with the paranoia of invasion literature and the onset of the Great War. These fears produced the British 1914 The German Spy Peril, centred on a plot to blow up the Houses of Parliament, and 1913's O.H.M.S.,[4] standing for 'Our Helpless Millions Saved' as well as On His Majesty's Service (and introducing for the first time a strong female character who helps the hero).
In 1928, Fritz Lang made the film Spies which contained many tropes that became popular in later spy dramas, including secret headquarters, an agent known by a number, and the beautiful foreign agent who comes to love the hero. Lang's Dr. Mabuse films from the period also contain elements of spy thrillers, though the central character is a criminal mastermind only interested in espionage for profit. Additionally, several of Lang's American films, such as Hangmen Also Die, deal with spies during World War II.