Dominant kingdoms included Mataram in Central Java, and the sultanates of Ternate and Tidore in the Maluku Islands to the east. By the end of the 13th century, Islam had been established in North Sumatra; by the 14th in northeast Malaya, Brunei, the southern Philippines and among some courtiers of East Java; and the 15th in Malacca and other areas of the Malay Peninsula. Although it is known that the spread of Islam began in the west of the archipelago, the fragmentary evidence does not suggest a rolling wave of conversion through adjacent areas; rather, it suggests the process was complicated and slow.