History of Cluj-Napoca - Principality of Transylvania

In 1541 Klausenburg became part of the autonomous Principality of Transylvania after the Ottoman Turks occupied the central part of the Hungarian Kingdom. Although Alba Iulia served as political capital for the Principality of Siebenbürgen (Transylvania), Klausenburg was the main cultural and religious center for the principality. In 1581, Stefan Batory, Governor of Transylvania, took the initiative in founding a Jesuit academy in Klausenburg.

Between 1545 and 1570, large numbers of Germans (Saxons) left the city due to the introduction of Unitarian doctrines. The remaining Germans were assimilated to Hungarians, and the city became a centre for Hungarian nobility and intellectuals. With the Treaty of Karlowitz in 1699, Klausenburg became part of the Habsburg Monarchy.