Islam spread throughout Southeast Asia between the 13th and 15th centuries as Muslim traders and missionaries traveled to the region. During this period, a number of influential sultanates were established by Muslim rulers in areas such as Sumatra, Java, the Malay Peninsula, and the southern Philippines. By the end of the 15th century, Islam had become the dominant religion in coastal areas of Southeast Asia and on major trade routes.

1. http://sites.asiasociety.org/education/islam_in_seasia/images/maps/03-EurasiaConversion.pdf