The origins of Castlevania

The idea to create Castlevania was inspired from early monster movies that came out in the early 20th century. The story of the game is loosely based upon the novel Dracula, written by Bram Stoker. Borrowing many of his weaknesses from the book (cross, bible, holy water specifically), his main weakness was a whip know as the Vampire Killer. The only people who could wield this whip were the Belmonts or those who are related to them by blood. The series first appeared as Akumajō Dracula  on the Family Computer Disk System in Japan in 1986 produced by the Konami game company. It gained attention when the game was released as Castlevania in the U.S. in 1987. These audiences embraced the game with high remarks.This highly remarked reception encourged Konami to establish Castlevania as a well known franchise.
http://castlevania.wikia.com/wiki/Castlevania_(video_game)