The subject of this research is the reconstruction of a biography in a broad sense, and in a narrow sense, the collaboration with the "Polish Party" of Vasily Osipovich Yanov, a representative of the Moscow bureaucratic elite during the Time of Troubles. Such a reconstruction is partially made possible by the discovery of previously unknown letters of V.O. Yanov to Prince Wadysaw, dated 1619 (these documents were once purchased by Academician Nikolai Petrovich Likhachev for his paleographic cabinet). The letters, written in Latin script with a mixture of Russian and Polish words, allow us to conclude that this prominent official had a sufficient command of the Polish language, which can likely be extrapolated to all representatives of the ruling elite of the Moscow state at that time. These documents have been analyzed both from a historical perspective and fragmentarily from a linguistic standpoint. We used general scientific methods (analysis, synthesis, comparison, induction, deduction) as well as specialized historical methods (historico-genetic, problem-chronological). In addition, we adhered to the principles of objectivity and historicism while writing the article. For the first time, three letters from Duma clerk Vasily Osipovich Yanov, written to Prince Wadysaw as the Moscow tsar on August 27, September 17, and September 20, 1619, have been translated into Russian and published. To convey the degree of Yanov's command of the Polish language to the reader, we italicized the Russian words written in Latin script. We have also come to the conclusion that Yanov's cooperation with the "Polish party" was not motivated by loyalty to Vladislav, whom he had "kissed the cross" as the Tsar of Moscow, but rather by material considerations (the former Duma clerk was not above deceiving the Tsarevich for his own benefit). Yanov's letters also testify to the difficulties of incorporating Smolensk and Seversk lands into the Commonwealth as a result of the Deulino Truce.
N. V. Eylbart (2026) studied this question.