ENStarting from the first half of the fourteenth century, the transumpty of notary instruments were willingly used in the practice of diplomacy between the Teutonic Order and Poland (and Lithuania). The advantage here lies with the Teutonic Knights, but this form was also known to their adversaries - the Polish side referred to this type of documents in the trials before Benedykt Makrai and Antoni Zeno. At the same time, the arsenal of Polish diplomacy’s means was to question the legal power of the Teutonic transumptions and to demand the presentation of the originals. At least verbally, the Teutonic Knights declared their readiness to do so, which proves that despite their efforts to strengthen the evidence position of the transumptions, they shared the view that the original documents were superior in this respect. Both parties eagerly used the services of public notaries to document legal actions related to mutual relations (e.g. reports on the ratification of the Kalisz peace, or the affixing of the seal of Bishop Jan Pella to the diploma of the Peace of Melno). Keywords: transumpt, notary instrument, public notary, Teutonic Order, Poland, Lithuania. [From the publication]