Throughout the contact period, Southeast Asia was part of an extensive trading network linking the Roman, Sassanian and Gupta Empires to the west  with the Chinese Empire to the east, stretching from Sri Lanka and the Coromandel Coast of the Bay of Bengal across the Andaman Sea to the Pyu and Mon city states of the Ayeyarwady deltas, over the isthmus of Kra or through the Straits of Malacca  to the thalassocratic Srivijaya trading empire of the Malayan peninsula and Sumatra and their Sailendra and Sanjaya feudatories in Java. It then crossed the Gulf of Thailand to the Dvaravati states of the Chao Phraya plain and delta to the north and entrepots in the Mekong Delta of today’s Viet Nam and thence into the South China Sea and the ports of southern China.(figure 2). 

Indian merchants presumably brought innovative religious and cultural beliefs along with new commodities to the region but there is no indication they exercised any direct political influence there, Instead, the rulers of the various polities along these shipping routes, who profited enormously from taxing this trade, seem to have first embraced these new religions along with Indian luxury goods, in contrast with their subjects, who continued to practice animism and subsistence farming. 

They adapted those aspects of these new religions which resonated with their own social and cultural belief, reinforcing rather than challenging traditional authority. Merchant states tended to favor Buddhism which downplayed caste distinctions, while the nobility were attracted to Hinduism’s sanction of hereditary prerogatives, such as the Khmer devaraja cult and celebration of kingship in the Indian epics, especially the Ramayana or Reamker in Khmer.  

Khmer ethnic groups are thought to have migrated during this contact period south from the area of Yunnan in China, before settling along the lower reaches of the Mekong River. Chinese chronicles, our only written sources for this period, mention a coastal trading partner and tributary in that area, Funan, and, beginning in the 6th Century, an inland kingdom they called Zhenla or Chenla, which seems to have gained suzerainty over the Khmer-speaking parts of Funan. A king, Isanavarman I, ruled this polity from 600-628 from Sambor Pre Kuk, a religious complex and site of the first indisputably Khmer temples,146 km southeast of the future Angkor. This nascent kingdom quickly dissolved into warring city states and local dynasties until Jayavarman II (790-835) reconstituted a Khmer Empire in 802 which flourished into the 14th Century. 


The transmission route of Indic culture to the Khmer remains uncertain since it is doubtful many members of this inland kingdom had direct experience of the subcontinent; it is quite possible that no one actively involved in commissioning a Khmer temple during the classical period had seen an Indian temple, except perhaps sketched on a palm frond manuscript. The epigraphic record, however, contains evidence of limited Khmer contact and trade with the Buddhist Srivijaya Empire of Palembang in Sumatra and the Sailendras of the Kedu Plain of Java, builders of the immense temple mountain, Borobudur, as well as their Hindu allies, the Sanjayas, responsible for the complex at Prambanan; stylistic analysis of early Khmer sculpture and architecture confirms these influences. Therefore Khmer knowledge of Indian architectural practice would have been second-hand at best, mediated through Javanese models, which would contribute to the divergence of Indian and Khmer ideas of a “temple mountain.”