The article examines the language of the personal letters of tsarina Evdokia, the first wife of Peter the Great, which were included in the printed text of a legal document, the manifesto of 1718. It describes a step-by-step investigation into the case of an alleged conspiracy against the tsar, at the center of which was Evdokia, by that time (since 1698) nun Elena. The choice of material for the article was dictated by the author's interest in the evolution of the business genres of the Russian office, a truly new stage of which occurred in the 18th century, a time of large-scale government reforms and, as a consequence, the restructuring of the entire system of business communication serving the work of the Russian Empire. Personal letters of the former tsarina, primarily addressed to her lover, childhood friend, officer of the Preobrazhensky regiment, Stepan Glebov, became a separate object for research for two reasons. Firstly, before the Manifesto of 1718 there were no public documents in which the internal unsightly aspects of the royal family life were publicly announced. Evdokia's love letters became available to the general public: the Manifesto was printed in two thousand copies and sold freely. Secondly, for the first time, a legal document that had all the signs of the clerical style of the early 18th century included love letters, creating a bright stylistic contrast with the general style of the business text. It is also known that Peter actively intervened in the draft text of the Manifesto, corrected the wording, and inserted entire fragments written in his own hand. Consequently, the printed text of the document, which was subject to mandatory publication, was important to the emperor in this form. The manifesto performs a number of important pragmatic functions in the conditions of the new Peter the Great era: in addition to the obvious informational, it has edifying, influencing and imperative functions.