By the 7th century, the harbours of various vassal states of Srivijaya lined both coasts of the Straits of Melaka. Around this time, Srivijaya had established suzerainty over large areas of Sumatra, western Java, and much of the Malay Peninsula. Dominating the Malacca and Sunda straits, the empire controlled both the Spice Route traffic and local trade. It remained a formidable sea power until the 13th century. This spread the ethnic Malay culture throughout Sumatra, the Malay Peninsula, and western Borneo. A stronghold of Vajrayana Buddhism, Srivijaya attracted pilgrims and scholars from other parts of Asia.