Pre-Angkorian history

Archaeological evidence indicates that parts of the region now called Cambodia were inhabited during the first and second millennia B.C. by peoples with a Neolithic culture. 

By the first century A.D., the inhabitants had developed relatively stable, organised societies, which had far surpassed the primitive stage in culture and technical skills. The most advanced groups lived along the coast and in the lower Mekong River valley and delta regions. 

There they cultivated irrigated rice and attended domesticated animals and developed trade due to their control over main waterways into China.

The Khmer people were among the first in Southeast Asia to adopt religious ideas and political institutions from India and to establish centralized kingdoms encompassing large territories. The earliest reports over the kingdoms of the Khmer can be found in Chinese travel reports.

According to these annals, the Khmer region was a highly developed and thriving state. It's capital had brick buildings and was situated in the current Vietnam and the port Oc Eo in the Gulf of Thailand controlled the traffic between China and India. The Khmer had an extensive fleet of naval vessels

An extensive system of waterways provided easy transportation and was also used for irrigation. 

Cambodia, situated at the lower Mekong River on great trade routes and controlled access to China. The kingdom of the Funan, one of the first to be known in Southeast Asia, adopted religious ideas, political institutions and technical expertise from India.

Its capital, Vyadhapura, probably was located near the present-day town of Phumi Banam in Prey Veng Province. The Funanese economy depended on rice surpluses produced by an extensive inland irrigation system. There is evidence that Funan had once been a strong maritime state, actively involving in sea trades.

Indian religion, political thought, literature, mythology, and artistic motifs gradually became integral elements. 

The caste system never was adopted, but Indianisation stimulated the rise of highly-organised, centralised states. Indian traders brought with them  knowledge and thoughts as well as philosophy and religious beliefs which significantly aided the development of this native kingdom.

The name 'Fu Nan', the name given to the kingdom by the Chinese, was derived from the Cambodian word phnom or mountain.

Fan Shih-Man (205-225) rules Funan according to Chinese dynastic history - The Liang-shu - relates that Fan Shih-Man "attacked and conquered the neighbouring kingdoms." 

A brake-away kingdom around the middle Mekong which assumed most of Funan in a short period of time covered large areas of Cambodia, Laos, Thailand and Vietnam.   In the 7th century it broke into two parts in : Land Chenla and Water Chenla. In 715, both Chenla states were further broken up into several smaller states.

In the eighth century Water Chenla was subjected to attacks by pirates from Java, Sumatra, and the Malay Peninsula. In the beginning of the ninth century, it had become a vassal of the Sailendra dynasty of Java. The last of the Water Chenla kings was killed around 790 by a Javanese monarch whom he had offended. 

What followed was that the ruler of a small Khmer state in north of the Mekong Delta assumed the throne. His assumption of the throne as Jayavarman II (ca. 802-50) marked the liberation of the Khmer people from Javanese and the beginning of a unified Khmer nation. 

Jayavarman II had been held hostage at the Java court in his youth. He returned to his country to liberate it from invaders and assumed kingship in 790.

He proclaimed himself to be a universal monarch of Khmer in a ritual ceremony borrowed from Hinduism as a "god-king" or deva-raja.  In the ritual, he worshipped god Shiva who was known by the Khmer for a long time as a god of protector.  As a god-king, King Jayavarman II had psychologically asserted his divine kingship over the Khmer of his absolute authority and sovereignty. At the same time, it was a declaration of Independence from Java.

After the establishment of Angkor kingdom, Jayavarman II expanded his territory  throughout Cambodia.  He built a temple devoted to god Shiva at Phnom Kulen about 40 km northwest of Tonle Sap