Based on new archival materials, the paper briefly highlights the history of V.V. Bartold’s research visit to Turkey in 1926, particularly, its preparation, reasons, and goals. It is shown that the invitation was made by the Turkish government and supported by the Academy of Sciences of the USSR and by the People’s Commissariat for Foreign Affairs. Bartold mostly spent his time in Turkey preparing a series of lectures on the history of Central Asian peoples at the request of the Turkish side, and studying Oriental manuscripts in Istanbul libraries. Besides, he was busy carrying out the mission entrusted to him by the Academy of Sciences, to establish academic contacts with Turkish researchers. The period of Bartold’s stay in Constantinople (Istanbul) from January 2 to February 17, was reflected in his small diary. In daily entries, the Academician thoroughly recorded events, meetings with Turkish and European researchers, made brief notes about manuscripts and libraries. He also noted his impressions of scientific institutions and changes in the cultural space of the former Ottoman capital. The research visit of the renowned orientalist Academician V.V. Bartold to Turkey was an important contribution to strengthening scholarly contacts between Russian and Turkish researchers. The part of the diary from January 2 to January 14, 1926, in which Bartold describes the first two weeks of his stay in Constantinople, is published as an appendix.