This lecture covers different versions of Moscow's strengthening: the geographic one as well as the social and political ones. The process of Moscow's gaining strength is studied in detail. Such princes as Daniil Aleksandrovich, Yury Danilovich and Ivan Kalita are mentioned. Dmitry Donskoy is spoken about as well as the Battle of Kulikovo and its consequences. The so-called feudal war is given an account of.