It was a time of mystical movements, Masonic lodges, interfaith Christianity, the Holy Alliance, the Patriotic War, the Decembrists, Pushkin and the heyday of Russian poetry. Then the Russian soul of the 19th century, its emotional life, was formed. The central place in this era was occupied by the figure of the Russian Tsar Alexander I, whom Nikolai Berdyaev called “the Russian intellectual on the throne.” But at the same time, he was a man who was always under suspicion of the most terrible sin - parricide... Not only the life, but also the death of Alexander I is a mystery for future generations. Popular rumors about his death turned into a legend, the authenticity of which is being tried by the famous French historian Henri Troyat.