It all started with "Frankenstein" (1931). Bela Lugosi had just finished his iconic role as Count Dracula in the Universal Studios classic monster film, "Dracula" (1931). Now Universal Studios wanted to keep the momentum going with the release of more monster films. Next would be a silver screen adaptation of Mary Shelley's novel, "Frankenstein." They immediately cast the Hungarian actor in the starring role as Frankenstein's monster.

However, the production ran into trouble when it came to Lugosi's complaints over the portrayal of the monster. In original script, he was a killing machine and Lugosi believed the character did not challenge him as an actor. "I was a star in my country and I will not be a scarecrow over here," Lugosi reportedly said. He took it step more when he said that any "half-wit extra" could play the role. He became increasingly more difficult to handle during make-up tests with artist Jack Pierce. Lugosi was indignant in having to wear, what he considered, such heavy material on his face. He was promptly kicked off the set and someone else had to fill the role.

Enter Boris Karloff, who was a relative unknown actor. Before he was cast in "Frankenstein", Karloff had made a few silent films but "Frankenstein" would catapult him into super-stardom. The film doubled "Dracula"'s profits at the box office. A year later, Karloff would play another iconic monster, Imohtep in "The Mummy" (1932). Also, Karloff would reprise his role two more times before the decade ended - "Bride of Frankenstein" (1935) and "Son of Frankenstein" (1939) and at least several more times during the course of his career.

While Karloff's star rose higher, film offers for Lugosi continued to dwindle. It is believed that he regretted the decision of ever turning down "Frankenstein", therefore embittered over Karloff's success.

But the "The Black Cat" (1934) would be the first film in which Lugosi and Karloss would co-star together. It seemed that a rivalry had already been established in the public's mind. Fabricated through Hollywood's media, the public believed a tense relationship was brewing on set. The publicity stunt did wonders for the box office and earned critical acclaim for "The Black Cat". The actual truth was, both actors were cordial and professional towards each other. After all, they would make an additional five films together.

Although there remains a question of Lugosi's bitterness towards Karloff but when Karloff heard of Lugosi's passing in 1956, he remarked, "Poor old Bela, he was worth a lot more than he got."

In 2012, daughter of Boris Karloff, Sara Karloff, and son of Bela Lugosi, Bela G. Lugosi, reunited at the Turner Classic Film Festival with the screening of "The Black Cat." During the interview by "The Hollywood Reporter", both confirmed that the rivalry between their fathers was all hype.