Lhe 14th century Arab chronicles rustle with a rumor. Beyond the Sahara desert, a black emperor, Mansa Moussa and his court crossed the lands of Islam on a pilgrimage to Mecca, staying in the capital of the then Islamic world, Cairo. Provided in gold and precious gifts, this demonstration of power and symbols reveals to the Muslim world, shaken by the power of the nomads of the steppes of Mongolian central Asia, that the spread of the revelation of Muhammad has built a backworld that is also the main source of supply of the empires in gold and slaves.