Wallachia
From Tardis Wiki, the free Doctor Who reference
According to the Fifth Doctor, Wallachia was, during at least the 15th century, a principality in what would become Romania by the 20th century. It bordered Transylvania. It was led by the Prince of Wallachia, and its capital city was Târgoviște.
In the 15th century, it was hotly contested between Christians, led by Dracula, and Muslims, led by the Turkish Mehmed II and aided by Radu the Handsome, Dracula's brother.