The Principality of Transylvania was a semi-independent state ruled primarily by Hungarian princes. Its territory, in addition to the traditional Transylvanian lands, also included the other major component called Partium, which was in some periods comparable in size with Transylvania proper. The establishment of the principality was connected to the Treaty of Speyer. However, Stephen Báthory's status as king of Poland also helped to phase in the name Principality of Transylvania. Although the principality was essentially independent, it existed as an Ottoman vassal state for the majority of the 16th and 17th centuries, overseen by Ottoman Turkish sultans but ruled by Hungarian princes. At various points during this period, the Habsburgs also exerted a degree of suzerainty in the region.

The Edict of Torda was a decree that authorized local communities to freely elect their preachers in the Eastern Hungarian Kingdom of John Sigismund Zápolya. The delegates of the Three Nations of Transylvania – the Hungarian nobles, Transylvanian Saxons, and Székelys – adopted it at the request of the monarch's Antitrinitarian court preacher, Ferenc Dávid, in Torda on 28 January 1568. Though it did not acknowledge an individual's right to religious freedom, in sanctioning the existence of a radical Christian religion in a European state, the decree was an unprecedented act of religious tolerance.