The Diploma Leopoldinum was a legal document which determined the basic principles of the government of the Principality of Transylvania within the Habsburg Empire. The diploma was drafted by Miklós Bethlen, Chancellor of Transylvania. The Holy Roman Emperor, Leopold I, sanctioned it in Vienna on 16 October 1690. The diploma restored civil administration in the principality, and confirmed the traditional liberties of the Three Nations of Transylvania, including the freedom of the four "received" religions.
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Diploma Leopoldinum Wikipedia(Text) CC BY-SA