Vlad Țepeș
A common misconception, or legend, if you will, is that of the vampire. When Bram Stoker toured Europe, he came upon the legend of Vlad Dracula, or Vlad Țepeș, and based his novel Dracula thereupon.
Vlad Țepeș' father started the Order of the Dragon, an order similar to the Knights Templar, which also apparently went corrupt later on. As a result of the order, Vlad II got the nickname of Dracul, meaning Dragon in Romanian. It also meant devil, probably influencing Bram Stoker as to the whole "satanic" portrayal of dracula in his novel. Vlad III consequently became known as Dracula, meaning "son of the dragon", or alternatively, "son of the devil".
There is a fair amount of uncertainty as to the whole blood drinking idea, as this was probably adapted to fit in another infamous person, Erzsebét Bathory, who, in the 1500s were believed to have killed about 650 people (virgin girls), and drank, and bathed in, their blood in the mistaken belief that it would grant her immortal youth and beauty, as she apparently was quite beautiful according to records.