High Quality Content by WIKIPEDIA articles! The Principality of Transylvania was a semi-independent state, ruled primarily by Hungarian princes. As a semi-independent state, the Principality existed from 1570 to 1711. Until the Turkish defeat in the Great Turkish War (1683-1697), it was under the suzerainty of the Ottoman Empire. After the Treaty of Karlowitz (1699), it was a vassal state of the Habsburg Monarchy.