Vladislav III, also known as Vlad the Impaler, was an actual historical figure. He was Prince of Wallahia who reigned three times between 1448 and 1476. His epithet, "Impaler", originated from his favoured method of executing those who opposed him. Vlad III is indeed widely speculated to have been the inspiration behind the title character of Bram Stoker's 1897 novel Dracula.
Despite being the son of a known vampire, it is unclear whether or not Vlad the Impaler is one as well. This is because little is known of vampires in J. K. Rowling's work, and whether it is possible for a person to be born a vampire or if they have to be "turned."