Transylvania as originally defined in Treaty of Trianon, 27 years earlier, thus confirming the return of Northern Transylvania to Romania. From 1947 to 1989, Transylvania, along with the rest of Romania, was under a communist regime. The ethnic clashes of Târgu Mureș occurred between ethnic Romanians and Hungarians in March 1990 after the fall of the communist regime and became most notable inter-ethnic incident in the post-communist era. The Transylvanian Plateau, high, is drained by the Mureș, Someș, Criș, and Olt rivers, as well as other tributaries of the Danube. This core of historical Transylvania roughly corresponds with nine counties of
History of Transylvania 895. This is supported by an eleventh-century Russian tradition that the Hungarians moved to the Carpathian Basin by way of Kiev. However, according to Florin Curta no evidence exists of Magyars crossing Eastern Carpathian Mountains into Transylvania. According to supporters of the Daco-Roman continuity theory, Transylvania was populated by Romanians at the time of the Hungarian conquest. Opponents of this theory assert that Transylvania was sparsely inhabited by peoples of Slavic origin and Turkic people. The year of the conquest of Transylvania is unknown; the earliest Magyar artifacts found in the region date to the first half of the 10th