Visayan regions, indicated that these peoples of Luzon were less influenced by the Hindu and Buddhist beliefs of the Madjapahit empire than the Visayans were. They also observed that the words were used alternately amongst the peoples in the southernmost portions of Luzon - the Bicol Region, Marinduque, Mindoro, etc. They suggested that this have represented transitional area, the front lines of an increased "Indianized" Madjapahit influence which was making its way north the same way Islam was making its way north from Mindanao. Foreign cultural influences Trade and cultural influences from China, India, and Maritime Southeast Asia The early inhabitants of the present-day Manila engaged in trade relations with its Asian neighbours as well as with the Hindu empires of Java and Sumatra, as confirmed by archaeological findings. Trade ties with China became extensive by the 10th century, while contact with Arab merchants reached its peak in the 12th century. Beginnings of Islamization in Luzon (1175 – 1500s) Archeological findings provide evidence that followers of Islam had reached the Pasig River area by 1175; among the graves found on the Sta. Ana burial site were a number of Muslim burials. Islamization was a slow process which occurred with the steady conversion of the citizenry of Tondo and Manila created Muslim domains. The Bruneians installed the Muslim rajahs, Rajah Salalila and Rajah Matanda in the south (now the Intramuros district) and the Buddhist-Hindu settlement was ruled under Lakan Dula in northern Tundun (now Tondo). Islamization of Luzon began in the sixteenth century when traders from Brunei settled in the Manila area and married locals while maintaining kinship and trade links with Brunei and thus other Muslim centres in Southeast Asia. The Muslims were called "Moros" by the Spanish who assumed they occupied the whole coast. There is no evidence that Islam had become a major political or religious force in the region, with Father Diego de Herrera recording that the Moros lived only in some villages and were Muslim in name only. Economic activities Historians widely agree that the larger coastal polities which flourished throughout the Philippine archipelago in the period immediately prior to the arrival of the Spanish colonizers (including Tondo and Maynila) were "organizationally complex", demonstrating both economic specialization and a level of social stratification which would have led to a local demand for "prestige goods". Specialized industries in the Tagalog and Kapampangan regions, including Tondo and Maynila,