The book presents correspondence between Alexander I and his sister, Grand Duchess Maria Pavlovna, as well as letters to Maria Pavlovna from Empress Elizabeth Alekseevna. The correspondence began in 1804, when Maria Pavlovna, having married the crown duke of Saxe-Weimar-Eisenach, settled in Weimar, where the great representatives of the Weimar classics - Goethe, Schiller, Wieland - were still alive. It ends with the death of Alexander. The last letters to Maria Pavlovna Elizaveta Alekseevna date back to 1826. The correspondence, which lasted more than twenty years, covers the era of the Napoleonic Wars, when the Duchy of Saxe-Weimar became a formal enemy of Russia, and the era of the repartition of Germany and the creation of the German Confederation at the Congress of Vienna, when both Alexander and Maria Pavlovna often used each other to decide political and diplomatic tasks. The appendix contains extracts from Maria Pavlovna’s correspondence with members of both her Russian and Weimar families, as well as letters from Russian writers to Maria Pavlovna. For the first time, Maria Pavlovna’s personal diary for the years 1805–1808 is also published in Russian.