Themes of Islamic Civilization Author:John Williams In AD 610, an Arab merchant called Muhammad founded a new religion called Islam. His teachings inspired the Arab peoples, and by 750 Muslims (followers of Islam) had conquered an area stretching from Afghanistan to AL ANDALUS in southern Spain. Trade, science, and culture thrived in this Islamic empire. Newly conquered lands were united by Islam... more », and by common tax systems, coinage, and laws. Jews and Christians sometimes paid higher taxes, but they were free to run their own religious affairs so long as they did not insult the Prophet Muhammad. Islam brought a new sense of unity and purpose to the traders and tribespeople of the Arabian Peninsula. Led by the CALIPH, Arab armies spread Islam in the Middle East and beyond. It helped that their main enemies, the Sassanids in Iran and the Byzantines in eastern Europe, were weakened by fighting each other. Islam was also spread by Muslim traders.« less