their own project to the detriment of the Lithuanians and which in course of the coming years deprived the Duchy of its own independent political standing. Lappo introduced major changes to this vision and partially presented his own perspective. Lappo carried out a fairly detailed reconstruction of the Sejm of Lublin and the circumstances of the conclusion of the Polish-Lithuanian union in 1569. He agreed that the Poles were bent on imposing their own terms of the union upon the Lithuanians, though unlike fellow Russian scholars he distinguished between different positions adopted by the king, the magnates and most of the nobility, expressed in somewhat diverse visions advocated by the Senate and by the Chamber of Deputies. Lappo's general attitude towards the Union of Lublin remained negative; he sympathized with Lithuanians, seeing Poles as merely caring for their own interests. Within the Russian historiography the innovative idea fathered by Lappo was that despite largely disadvantageous terms of the Union, the Grand Duchy retained its political identity and remained the subject of political game, both within the Commonwealth and internationally. He analysed in detail both the legal framework and the praxis; this provided him with arguments that the Crown of Poland has never managed to turn the Duchy into its province, and that when in the early 18th century Lithuania gradually became the object of politics it was rather because of international developments, especially against the background of the Swedish-Russian conflict. Reception and legacy Despite running against the main current, Lappo's graduation thesis was very well received; reviewers noticed attention to detail, great command of sources and holistic approach with wide coverage of the background. Some criticism was related to his alleged bias, reportedly stemming from sort of Lithuanian patriotism. The reception led to offering him the prestigious chair of Russian history in Juriev at the relatively young age of 36. Continuation of his work, formatted as a PhD thesis, was also widely acclaimed. The rector of the Moscow University Matvey Kuzmich Lyubavskiy suggested that Lappo's work be awarded the Karpov prize, he obtained long-term research contracts and was gradually emerging as a rising star of the Russian historiography. Lappo's career in academic structures of imperial Russia was terminated due to political turmoil and revolution. When on exile in Czechoslovakia his work suffered from limited access to sources. His studies on national identities on western Russian borderlands are considered of lower