This article analyzes the toponymic bindings that accompanied the dating of the diary entries of Grand Duke Michael Alexandrovich. Since the author, a prominent representative of the Russian Imperial House, who was successor to the throne for some time, became a major military, state and public figure, his diaries should be recognized as a particularly valuable historical source. It is indicated exactly how the Grand Duke made bindings to the area where he was on a particular day, including during his travels. A comparison is made of the toponymic bindings given by Grand Duke Michael Alexandrovich with the presence and peculiarities of such bindings in the diaries of his closest relatives - parents (Emperor Alexander III and Empress Maria Feodorovna), brothers (Emperor Nicholas II and Tsesarevich George Alexandrovich) and sisters (Grand Duchess Xenia Alexandrovna and Grand Duchess Olga Alexandrovna). The diaries of Grand Duke Michael Alexandrovich and his relatives have been deposited in the State Archive of the Russian Federation, in the personal provenance funds of the authors. Based on the comparative analysis, the greatest similarity of the style of toponymic bindings characteristic of Grand Duke Michael Alexandrovich is revealed with similar bindings of his father, Emperor Alexander III, and his younger sister, Grand Duchess Olga Alexandrovna, which confirms the statements found in the literature about the monarch's particularly close relations with younger children. The article is illustrated with fragments of the diaries of members of the Russian Imperial House. The study was conducted as part of a project of the Russian Science Foundation aimed at preparing for the scientific publication of the previously unpublished full text of the diary entries of Grand Duke Michael Alexandrovich during the years when he was successor to the throne.