The Mongols invaded Kievan Rus in the 13th century and destroyed multiple cities including Moscow, Kiev, and Vladimir. All Rus leaders had to submit to Mongol rule or face capital punishment such as beating, hanging, Execution, or branding of the skin. Under Mongol rule, Muscovy developed: a social hierarchy with Senior nobility at the forefront (behind the tsar/king), census, postal service network and routes, military, and fiscal system. Under their rule, the Mongols put into place Muscovy princes who were lucky, determined, and ambitious.