Choosing four classic genre favorites is almost impossible. So,  instead, these are four of the most influential classic horror movies ever made. Admittedly, maybe they are not movies that initially come to mind. And, they are not choices always available in the United States, but these films are considered unquestionably iconic — genre-defining horror movies.

The Cabinet of Dr. Caligari (1920)

Robert Wiene’s The Cabinet of Dr. Caligari is a stylized nightmare of abstract locations and violent landscapes. It is widely considered the birth of cinematic horror for the overall genre..

The film stars German-born actor-director Conrad Veidt as the murderous somnambulist villain, Cesare. With the rise of the Nazi Party, Veidt fled from Germany to Great Britain. Veidt was best known for his portrayal of Gestapo Maj. Strasser in the classic Casablanca (1942) – where he was the highest-paid actor, so it is interesting, indeed his historical contribution to the genre.

Also starring Werner Krauss as Dr. Caligari, the 1920s black and white film is considered a masterpiece of German expressionism, using stark contrasts and sharp angles to confuse the senses. Enhanced by visual stimuli, the dream-like intensity of each scene results in a horrifying film that communicates the fear and mistrust of the isolated post–World War I culture.

First released in February 1920, The Cabinet of Dr. Caligari’s initial box office gross was $4,713. Highly recommended, with a  runtime of less than one hour; The Cabinet of Dr. Caligari is available to rent on Amazon Prime Video, and is a defining creation within the horror genre.

Cat People (1942)

Directed by Paris-born Jacques Tourneur, Cat People (1942) was Hollywood’s first true low-budget horror success story for the genre. Written by DeWitt Bodeen, the film was overseen by David O. Selznick’s assistant, Russian-born horror-producer, Val Lewton. Viewed by many as the beginning of this Lewton’s influential and infamous career, the film was credited with saving the financially failing RKO Studios.

This landmark production, a pre-cursor to Indie-style filmmaking for the horror genre, signed an entire cast of unknowns, including Simone Simon, Tom Conway, and Kent Smith.

The film’s plot is simple. A New York marine engineer Oliver Reed marries East Russian immigrant Irena Dubrovna — a fashion sketch artist. Dubrovna fears that, descended from evil, she will transform into a fabled Serbian cat person on their wedding night.

This genre classic was filmed in just 18 days and rumored to have directly influenced Alfred Hitchcock. However, the Cat People‘s revolutionary contribution to the horror genre is from its iconic “bus scene.” This tension-filled scene is credited with the birth of “jump scares” — devices that continue to serve as horror’s most effective scare methods.