The issue of conferring the Duchy of Opole-Racibórz as a pledge to Gábor Bethlen, the Prince of Transylvania, is still waiting to be thouroughly studied. So far, not a single separate dissertation, article or monoograph has been devoted to it, except one valuable yet now completely antiquatwd work by Veress, which relates to it only partially. Apart from that, more or less accurate reference on the subject are found in numerous studies concerning the Thirty Years’ War: The purpose of this article is to present this on the basis of yet unexplored archival materials and literature of the subject…