Mario Bava was an influencial Italian director known for his horror films. He started his career as a cinematographer befor turning to directing. He is known for his Gothic horror films and the start of the giallo genre of films with films like The Girl Who Knew Too Much. The Bay Of Blood has the reputation as the start of the slasher genre of films. Planet Of The Vampires is considered theoriginal idea behind the film Alien. The Day The Sky Exploded is considered the first Italian sci-fi film which he effectively directed although he is not credited as director.