What is the history of Dracula and vampire myth?

I know he was based on the notorious Vlad the Impaler, who was as bad as he sounds, but where did all the vampire stuff come from, and why was this one medieval warlord (Vlad) chosen out of the endless to pick from? Was Vlad known as a vampire from his time to now, or did that start with Stoker in the Civil War era? Also, how long have vampire myths and legends been around the Eastern Europe area where Dracula is supposed to be from?