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
Principality of Transylvania (1570–1711) West and north Royal Hungary, Ottoman Hungary, and the Eastern Hungarian Kingdom under Ottoman suzerainty, which later became the Principality of Transylvania where Austrian and Turkish influences vied for supremacy for nearly two centuries. The Hungarian magnates of Transylvania resorted to policy of duplicity in order to preserve independence. Transylvania was administrated by Isabella, John Sigismund's mother from 1541 to 1551, when it fell for 5 years (1551–1556) under Habsburg rule. The House of Zapolya gained again the control of Transylvania in 1556, when the Diet of Szászsebes elected Sigismund as prince of Transylvania. Transylvania was now beyond the reach