ENMichal Römer (1880–1945) came from a noble-landowning family settled in the territory of the Grand Duchy of Lithuania in the 17th century. During the 1905 Revolution, he participated in the Polish democratic milieu in Vilnius, while supporting the activities of social and cultural organizations created by the Lithuanian national movement. He participated in public discussions on the nature of the so-called national idea, the foundation of which was the desire to build on the territory of the former Grand Duchy. Römer’s variant of the national idea took its final shape during the First World War. He assumed that only the Lithuanian national movement could be the host country – Lithuania in the realities of the 20th century, with Vilnius as the capital. He accused the majority of Poles living in the lands of the former Grand Duchy of Lithuania of refusing to recognise the legitimacy of the Lithuanian national movement’s aspirations and succumbing to a “borderland mentality”; they sought to deepen the polonisation of Lithuania, deprived it of its subjectivity and absorb it into the Polish state. Unable to come to terms with such perceived Polish policy and the attitude of the majority of Poles towards Lithuania, he decided to accept Lithuanian citizenship and settled in Kaunas in 1920.The article shows how important a role in the formation of Michal Römer’s ideological and political stance was played by two places with which he remained connected throughout his life – his hometown Bogdaniškės and Vilnius – where he spent a large part of his youth and the years of the Second World War. In the case of Bogdaniškės, a village in ethnic Lithuania, the process of development of social and political relations proceeded as expected by the protagonist of the text. Gradually, the emancipation of the Lithuanian countryside progressed and the Lithuanian state gained a strong social base, including a part of the Polish population, which gradually adapted to function in a lithuanised public space. For Römer, Vilnius was a symbol of Lithuania and, simultaneously, a historical challenge to national Lithuania. He personally dreamt of working out a compromise that would allow the city to become a viable Lithuanian capital while preserving the rights of Vilnius Poles to cultivate their own identity. However, in the face of events in the sphere of realpolitik, both in 1920 and during the Second World War, he actively supported the forcible lithuanianisation of Vilnius.