The document provides information about the Byzantine Empire, Russian Empire, and Turkish Empire between 500-1500 CE. It discusses how the Byzantine Empire survived the fall of Rome and expanded under leaders like Justinian before experiencing attacks and plague that weakened it. It outlines the development of river trade networks and cities in Russia, including Kiev adopting Orthodox Christianity, before the Mongol invasion disrupted the region. It also summarizes the rise of Turkish peoples within the Abbasid Empire and the establishment of the Seljuk Empire centered in Isfahan before conflicts with Crusaders and conquest by Mongols.