Jayavarman II founds the Khmer Empire

In 802 CE, according to later inscriptions, a ruler named Jayavarman II held a ceremony on Phnom Kulen, a sandstone plateau northeast of Angkor, and proclaimed himself a universal monarch, a chakravartin. The rite also set up the cult of the devaraja, or god-king, linking the ruler with the Hindu god Shiva. The ceremony is taken as the founding of the Khmer Empire, which dominated mainland Southeast Asia for roughly six centuries and left Angkor Wat as its best-known monument.¹²

Before 802 the lands of what is now Cambodia were split among rival chiefdoms, remembered in Chinese records as Funan and Chenla. The Khmer elite had absorbed Indian religion, writing and ideas of kingship through trade across the Bay of Bengal, much as the maritime empire of Srivijaya had done in Sumatra. An inscription of 1052 says Jayavarman II came from Java and freed his people from foreign overlordship, though historians still debate whether this means Java, Champa or somewhere else. He moved his court between several capitals, including Hariharalaya near Roluos, which later grew into Angkor.¹²

His successors built on this base with a system of reservoirs, canals and rice fields that supported a large population. Suryavarman II raised Angkor Wat in the early 1100s, and Jayavarman VII built the Bayon and a network of hospitals and roads in the late 1100s and early 1200s, turning to Buddhism. The empire weakened after 1300 under pressure from the Thai kingdom of Ayutthaya, climate swings and changing trade routes. After the Siamese sacked Angkor in 1431, the Khmer court moved south to the Phnom Penh area, and Angkor faded as a capital while remaining a place of worship.¹³