Between 500 and 800 CE, the Byzantine and Islamic empires were the most powerful forces in Europe, North Africa, and the Middle East. Each had a single ruler (the Byzantine emperor and the Islamic caliph) and each sought to spread a monotheistic faith (Christianity and Islam). Choose either the Byzantine or Islamic empires and identify two factors that made it successful. Then, find two similarities between Christianity and Islam. Do you think religion played a role in the success of the empires?