The book "Description of Ukraine" by the French military engineer Guillaume Levasser de Beauplan is a valuable historical source for studying the life of the Zaporizhzhya Cossacks and peasantry, as well as other states of medieval society in Ukraine. It reflects the geographical environment, the nature of Ukraine, its climatic conditions, provides data on the history of the settlement of the Middle Dnieper, depicts a vivid picture of the life of the Ukrainian people in the first half of the 17th century.