Book 1 is the first part of a study on the history of Ukraine of the XIII-XVII centuries. Starting from 1240, the author examines in detail the events associated with the liberation of Ukrainian lands from the Tatar yoke and their entry into the Grand Duchy of Lithuania and the Kingdom of Poland. Part 1 of Book 2 is a chronological continuation of the study of the Lithuanian-Polish period in Russian history. The reign of the overlords of the Grand Duchy of Lithuania and the Kingdom of Poland, Vladislav III, Casimir IV, Jan-Albrech and Alexander are considered by the author against the backdrop of the fall of the Byzantine Empire, the growing Turkish-Crimean threat and the growing power of Muscovy.