It think it should be "Wallachia" or "Wallachian Empire", since Romania only came into being in 1859, 500 years later than the reign of Vlad III.
He was also known as:
* "Tepes", pronounced Tseh-pehsh, meaning Impaler.
* "Dracul", pronounced Drah-cool, meaning The Devil, and transformed by Stocker in Dracula.