Following its foundation in the 7th century, Islam acted as a cohesive force between areas where it was established as the main religion. It facilitated trade between the lands of Christianity in west and the empires of the Far East via a number of important land and maritime trade routes. The most important early Islamic cities of Mecca and Medina were the fulcrum of these trade routes. The success of the early Islamic Empires, such as the Umayyad and Abbasid Caliphates, helped establish the ports of the Red Sea and Persian Gulf as important terminals for maritime trade. The spice trade with ports in India and the powerful Srivijaya Empire, which was dominant in Southeast Asia between 700–1300, also helped spread Islam. On land, the Silk Road trade route through central Asia, which was often contested with the powerful Mongolian Empire, helped establish rich trading cities such as Baghdad.
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