The third book of the capital anthology of M. M. Stasyulevich "History of the Middle Ages" covers the XII-XIII centuries and is dedicated to the events of the Crusade era. When presenting their history, the compiler used the works of not only Christian authors, but also Muslim sources. The anthology of M. M. Stasyulevich has been considered an indispensable book for those who teach and study the history of this period for almost a century and a half.