ENThe purpose of this study was to analyse privileges of the nobility conferred on the Lithuanians by Polish kings in the 15th-16th centuries and issued by the chancery of the Grand Duchy of Lithuania as opposed to those issued by the Polish Crown chancery. The differences resulted from the fact that the king of Poland who was also the Grand Duke of Lithuania, in compliance with Lithuanian laws based on three legal codes of 1529, 1566 and 1588, had a great deal of freedom in granting titles of nobility which tended to be a dynamic process determined by social, political and economic situation that influenced all those attempting to receive the Polish nobility status. These conditions had an impact on establishing laws what was reflected in the work of the Polish royal chancery. Along with a royal patent of nobility, similarly to other documents, its formulary was created, according to the patterns taken from foreign chanceries. Preparing and creating a patent of nobility was long-term process conditioned not only by diplomatic formulae, but also by individuals responsible for issuing a document as well as its beneficiary. The content, formulae and shape of the manuscript (the size of parchment, calligraphy, illuminations, the way to depict a coat of arms and a coat of arms itself) depended on the recipient and his social status. Lithuanian letters patent of nobility were issued in three languages: Latin, Russian and Polish. Diplomatic formulae included in these acts are similar to those existing in documents produced by the Polish royal chancery whose formulary originated in the 15lh and at the beginning of the 16lh centuries.There were twelve diplomatic formulae: invocation, formula perpetuatis, preamble, superscription (or entitling) along with Dei gratia (by the Grace of God) formula, notification, exposition, disposition, corroboration, date, list of witnesses, formula “datum per manus” (“given by the hand of”) and subscription that have been distinguished and described with reference to the Polish Crown chancery and the chancery of the Grand Duchy of Lithuania. The former chancery issued documents mainly in Latin, whereas the latter in Latin and Russian. The differences which refer to both groups of languages are particularly visible in the formularies of documents issued by the Russian office in the chancery of the Grand Duchy of Lithuania since they do not include invocation, formula perpetuatis or preamble. Invocation which commences patents of nobility based on extended formulary was often written with the use of bigger letters compared to the rest of text body, as a clearly visible composition. In this group of documents formula perpetuatis appears in the same form: “Ad perpetuam rei memoriam” (“For the memory of the act in perpetuity”). The preamble expresses motivation of the action, the reason for which the document was created. It consists of general considerations on the transitory nature of human actions until the moment when certified diploma has been issued. In letters patent of nobility, preamble is composed of deliberations on particular favour of the ruler and his will to reward the subjects for their exceptional services in justification of conferring the privilege. The preamble is usually followed by the superscription and formula perpetuatis with the content typically adjusted to this kind of letters patent. It appears in all the Lithuanian letters patent of nobility written in Latin due to the formulary created in the Crown chancery.As far as Lithuanian privileges of the nobility of the 15th and 16th centuries are concerned, the preamble is not included in one diploma only. It is the letter patent of nobility, issued in 1525 for Michal Józefowicz, non-baptized Jew, based on the formulary created in the chancery of the Grand Duchy of Lithuania for the letters patent of nobility written in Russian which normally lack invocation, formula perpetuatis and preamble. Superscription comprises the name, title, the office of the person issuing the document and is usually combined with Dei gratia formula which sovereigns added to their titles to indicate that the authority to issue such documents was given by God. The entitling is one of the most important formulae of the protocol, that is, the first part of the document. It is included both in letters patent of nobility based on extended formulary produced by the Crown chancery and in those based on abridged formulary created in the chancery of the Grand Duchy of Lithuania. In documents issued by the latter chancery the three formulae preceding superscription virtually do not occur. The entitling within the documents discussed in this study was influenced by territorial and legal transformations which happened in the reign of subsequent sovereigns of Poland and the Grand Duchy of Lithuania. Discussion about these documents requires a certain degree of circumspection due to the superscription which was often abridged in the copies of the Lithuanian letters patent of nobility included in the royal chancery records known as the Lithuanian Metrica and the Crown Metrica. An attempt to the king was either new or adopted (often by extension). It used to be depicted in the middle or at the side of the letter patent of nobility. If there was no space left inside the text, a margin was created to place the image of arms in its new iconographic pattern.[...].