A German adventurer who lived in Muscovite Rus' in the 16th century left rare historical evidence. His notes, found in archives only in the twentieth century, significantly changed previous ideas about the era of Ivan the Terrible. They are especially valuable because the author was a direct participant in the events, served as the tsar’s guardsman, was in the thick of what was happening and even, according to him, personally met with the sovereign. Von Staden gives a description of the administrative structure of Muscovy at that time, its judicial system and troops. Provides a list of the most important “offices” - orders, vividly and figuratively reproduces the principles of their functioning, names the names of the most influential princes and boyars at that time. He characterizes Moscow and the Kremlin in sufficient detail, and his description of the oprichnina court, which existed for less than five years before it was completely burned by the Crimean Khan in 1571, is truly unique.