Main article: Kingdom of Funan
At about the time that Western Europe was absorbing the classical culture and institutions of the Mediterranean, the people of mainland and insular Southeast Asia were responding to the stimulus of a civilization that had arisen in India during the previous millennium. The Indianization of Southeast Asia happened as a consequence of the increasing trade in the Indian Ocean. Vedic and Hindu religion, political thought, literature, mythology, and artistic motifs gradually became integral elements in local Southeast Asian cultures. The caste system was never adopted, but Indianization stimulated the rise of highly-organized, centralized states. Funan, the earliest of the Indianized states, is generally considered to have been the first kingdom in the area. Found in the 1st century CE, Funan was located on the lower reaches of the Mekong River delta area, in what is today southeast Cambodia and the extreme south of Vietnam. Its capital, Vyadhapura, probably was located near the present-day town of Ba Phnom in Prey Veng Province. The earliest historical reference to Funan is a Chinese description of a mission that visited the country in the 3rd century. The name Funan is largely believed to derive from the old khmer word 'Phnom' meaning mountain. The Funanese were likely of Austroasiatic origin. What the Funanese called themselves, however, is not known. During this early period in Funan's history, the population was probably concentrated in villages along the Mekong River and along the Tonle Sap River below the Tonle Sap. Traffic and communications were mostly waterborne on the rivers and their delta tributaries. The area was a natural region for the development of an economy based on fishing and rice cultivation. There is considerable evidence that the Funanese economy depended on rice surpluses produced by an extensive inland irrigation system. Maritime trade played an extremely important role in the development of Funan, and the remains of what is believed to have been the kingdom's main port, Oc Eo (O'keo) (now part of Vietnam), contain Roman as well as Persian, Indian, and Greek artifacts. By the 5th century, the state exercised control over the lower Mekong River area and the lands around the Tonle Sap. It also commanded tribute from smaller states in the area now comprising northern Cambodia, southern Laos, southern Thailand, and the northern portion of the Malay Peninsula. Indianization was fostered by increasing contact with the subcontinent through the travels of merchants, diplomats, and learned Brahmins. By the end of the 5th century, the elite culture was thoroughly Indianized. Court ceremony and the structure of political institutions were based on Indian models. The Sanskrit language was widely used; the laws of Manu, the Indian legal code, were adopted; and an alphabet based on Indian writing systems was introduced. Beginning in the early 6th century, civil wars and dynastic strife undermined Funan's stability. A former northern vassal turned to independent kingdom, Chenla, began to increase its power and status quo was achieved only through dynastic marriages. But eventually Funan was absorbed by the Khmer Chenla and became a vassal itself. Funan disappears from history in the 7th century. Chenla
Main article: Chenla Kingdom
The people of Chenla were Khmer and wrote in Khmer script, as opposed to the Funan practice of writing in Sanskrit. Chenla is first mentioned in the Chinese Sui History as a Funan vassal. The founder of the kingdom, who managed to break free from Funan's control, was Strutavarman. A later king, Bhavarman, invaded Funan annexing it to Chenla's domains. Once they...