Chinese merchants arrived in the 8th century. The rise of powerful Buddhist kingdoms enabled trade with the Indonesian archipelago, India, Japan and Southeast Asia. Factional fighting among the kingdoms of Southeast Asia weakened their strength. In the meantime, the spread of Islam through commerce and proselytism, much like Christianity, brought traders and missionaries into the region; Arabs set foot in Mindanao in the 14th century. When the first Europeans arrived, led by Ferdinand Magellan in 1521, there were rajahs as far north as Manila, who historically were tributaries of the kingdoms of Southeast Asia. However, the islands were essentially self-sufficient and self-ruling.