Celts in Transylvania arrived in northwestern Transylvania in around 400–350 BC as part of their great migration eastwards. When Celtic warriors first penetrated these territories, the group seem to have merged with the domestic population of early Dacians and assimilated many Hallstatt cultural traditions. The second half of the 4th century BC saw the Middle La Tène Celtic culture emerge in north-western and central Dacia, a development reflected especially in burials of the period. Celtic artifacts dating to this time have been discovered at Turdaş, Haţeg and Mediaş in modern-day Romania. By 1976, the number of Celtic sites found in Transylvania had reached
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