When was redeemed that great shame of my nation, the shame of Cassova, when the flags of the Wallach and the Magyar went down beneath the Crescent, who was it but one of my own race who as Voivode crossed the Danube and beat the Turk on his own ground? This was a Dracula indeed! Woe was it that his own unworthy brother, when he had fallen, sold his people to the Turk and brought the shame of slavery on them!
Bram Stoker in his novel Dracula and his short story "Dracula's Guest" presents the eponymous Count Dracula as a vampire from Wallachia; the character may have been loosely based on the historical Vlad Tepes, known as Dracula; "Dracula" meaning "Son of the Dragon," because his father, Vlad II Dracul, was a member of the Order of the Dragon, a Christian chivalrous order. Much of the fictional Dracula's history is left unspoken, including most of the real-life Vlad Dracula's most famous exploits, so identification is a bit vague, although the passage above suggests that the fictional Dracula is at least of the same family line as Vlad Tepes.
Raymond McNally and Radu Florescu in Searching for Dracula give a decent overview of both the historical voivode and Stoker's fictional vampire. Vampire lore was filtering into English literature at this point, especially John Polidori's The Vampyre (1819), Varney the Vampire or The Feast of Blood (1845-1847), and J. Sheridan le Fanu's Carmilla (1872), but the actual writing of Dracula occasioned seven years of research on Romania, Transylvania, vampires, and other matters (and quotes some of the material verbatim in the book), during which time Stoker encountered the name "Dracula" and became enamored with it, using it for his villain.
The identification of Count Dracula with the voivode Vlad Tepes was a bit later, and in various adaptations and usage of the character by other creators the connections have waxed and waned; Bela Lugosi's famous and enduring image of Count Dracula in the Broadway performance (1928-1929) and the subsequent film (1931) long established the image of the Count as a clean-shaven man dressed in an opera cloak, which still persists in many depictions of vampires to this day - but was far away from the famous portrait of the real-life Vlad Tepes, with his long hair and great mustache.