Although it is difficult to know precisely the early development of Islam in the archipelago (due to a lack of information sources), it is quite clear that international trade is a very important factor.
The possibility of Muslim traders from different countries has existed in the maritime region of Southeast Asia since the beginning of Islam. The earliest sources reported that a number of indigenous peoples had embraced Islam since the early 13th century; a new tombstone shows the existence of a Muslim empire in North Sumatra in 1211.
Perhaps the local kingdom adopted this new religion because it could give certain advantages in trade with most Muslim traders. It is unclear why indigenous peoples seem to have converted to Islam after centuries of religion are known in the region. It was not until the fifteenth century and later, the Islamic empire and the Islamic sultanate became the dominant political force in these islands, although later defeated by newcomers from Europe (Portuguese and Dutch) in the 16th and 17th centuries.
