Spy fiction is a genre of literature involving espionage as an important context or plot device. It emerged in the early twentieth century, inspired by rivalries and intrigues between the major powers, and the establishment of modern intelligence agencies. It was given new impetus by the development of fascism and communism in the lead-up to World War II, continued to develop during the Cold War, and received a fresh impetus from the emergence of rogue states, international criminal organizations, global terrorist networks, maritime piracy and technological sabotage and espionage as potent threats to Western societies. As a genre, spy fiction is thematically related to the novel of adventure (The Prisoner of Zenda, 1894, The Scarlet Pimpernel, 1905), the thriller (such as the works of Edgar Wallace) and the politico-military thriller (The Schirmer Inheritance, 1953, The Quiet American, 1955).