Transylvania modern Romania. The plateau is almost entirely surrounded by the Eastern, Southern and Romanian Western branches of the Carpathian Mountains. The area includes the Transylvanian Plain. Other areas to the west and north are widely considered part of Transylvania. In common reference, the Western border of Transylvania has come to be identified with the present Romanian-Hungarian border, settled in the 1920 Treaty of Trianon, though geographically the two are not identical. Ethnographic areas: The area of the historical Voivodeship is . The regions granted to Romania in 1920 covered 23 counties including nearly (102,787–103,093 km in Hungarian sources and 102,200
Northern Transylvania After the Roman legions withdrew in 271 AD, it was overrun by a succession of various tribes, bringing it under the control of the Carpi, Visigoths, Huns, Gepids, Avars and Slavs. From 9th to 11th century Bulgarians ruled Transylvania. The Magyars conquered much of Central Europe at the end of the 9th century and for almost six hundred years, Transylvania had been a voivodeship in the Kingdom of Hungary. After the Battle of Mohács in 1526, and the Hungarian defeat by the Ottomans, Transylvania became a semi-independent principality (Principality of Transylvania) under native Hungarian rule but owing suzerainty to the