The history of thriller films document traces the origins and evolution of the thriller genre from the 1920s onwards. It notes that Alfred Hitchcock released some of the earliest defining films of the genre like "The Lodger" in 1926. Throughout the 1930s and 1940s, Hitchcock and other British directors continued developing conventions of the genre. By the 1950s, classics like "Strangers on a Train" brought vast audiences to thrillers. Over subsequent decades, subgenres like psychological thrillers gained popularity as the genre became more defined and popular with new influential films released.