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
History of Transylvania (and briefly under Habsburg suzerainty) until 1602. The younger Stephen Báthory, a Hungarian Catholic who later became King Stephen Báthory of Poland, tried to maintain the religious liberty granted by the Edict of Turda but interpreted this obligation in an increasingly restricted sense. Under Sigismund Báthory, Transylvania entered the Long War, which began as a Christian alliance against the Turks and became a four-sided conflict in Transylvania involving the Transylvanians, Habsburgs, Ottomans and the Romanian voivod of Wallachia led by Michael the Brave. Michael gained control of Transylvania (supported by the Szeklers) in October 1599 after the Battle of Șelimbăr,