Srivijayan Empire (7th–13th century)

Srivijaya, a maritime empire centered at Palembang on the island of Sumatra in Indonesia, adopted Mahayana and Vajrayana Buddhism under a line of rulers named the Sailendras. Yijing described Palembang as a great centre of Buddhist learning where the emperor supported over a thousand monks at his court. Atisha studied there before travelling to Tibet as a missionary.
Sriviijaya spread Buddhist art during its expansion in Southeast Asia. Numerous statues of Bodhisattvas from this period are characterized by a very strong refinement and technical sophistication, and are found throughout the region. Extremely rich architectural remains are visible at the temple of Borobudur (the largest Buddhist structure in the world, built from around 780 CE), in Java, which has 505 images of the seated Buddha. Srivijaya declined due to conflicts with the Chola rulers of India, before being destabilized by the Islamic expansion from the 13th century.

Khmer Empire (9th–13th century)

Later, from the 9th to the 13th century, the Mahayana Buddhist and Hindu Khmer Empire dominated much of the South-East Asian peninsula. Under the Khmer, more than 900 temples were built in Cambodia and in neighboring Thailand. Angkor was at the center of this development, with a temple complex and urban organization able to support around one million urban dwellers. One of the greatest Khmer kings, Jayavarman VII (1181–1219), built large Mahayana Buddhist structures at Bayon and Angkor Thom.