The fictional character 'Dracula' was based on which European king?

Published in 1897, Bram Stoker’s Gothic novel Dracula launched an entire genre of literature and film about vampires, those sinister figures who use their supernatural powers to hunt humans and drink their blood. To create his immortal antihero, Count Dracula, Stoker certainly drew on popular Central European folktales about the nosferatu (“undead”), but he also seems to have been inspired by historical accounts of the 15th-century Romanian prince Vlad Tepes, or Vlad the Impaler. Born in Transylvania as the second son of the nobleman Vlad II Dracul, he took the name Dracula, meaning “son of Dracul,” when he was initiated into a secret order of Christian knights known as the Order of the Dragon.

Source: History