The sparse evidence for a Pleistocene human occupation of present day Cambodia are quartz and quartzite pebble tools found in terraces along the Mekong River, in Stung Treng and Kratié provinces, and in Kampot Province, but their dating is unreliable.[9]
Some slight archaeological evidence shows communities of hunter-gatherers inhabited Cambodia during Holocene: the most ancient Cambodian archeological site is considered to be the cave of L'aang Spean, in Battambang Province, which belongs to the so-called Hoabinhian period. Excavations in its lower layers produced a series of radiocarbon dates as of 6000 BC.[9][10]
Upper layers in the same site gave evidence of transition to Neolithic, containing the earliest dated earthenware ceramics in Cambodia[11]
Archeological records for the period between Holocene and Iron Age remain equally limited. Other prehistoric sites of somewhat uncertain date are Samrong Sen (not far from the ancient capital of Oudong), where the first investigations began in 1877,[12] and Phum Snay, in the northern province of Banteay Meanchey.[13] Prehistoric artifacts are often found during mining activities in Ratanakiri.[9]
The most outstanding prehistoric evidence in Cambodia however are probably various "circular earthworks", discovered in the red soils near Memot and in the adjacent region of Vietnam as of the end of the 1950s. Their function and age are still debated, but some of them possibly date from 2nd millennium BC at least.[14][15]
A pivotal event in Cambodian prehistory was the slow penetration of the first rice farmers from the North, which begun in the late 3rd millennium BC. They probably spoke ancestral Mon-Khmer.[16]
Iron was worked by about 500 BC, with supporting evidence coming from the Khorat Plateau, which is now in modern day Thailand. In Cambodia, some Iron Age settlements were found beneath Angkorian temples, like Baksei Chamkrong. Others were circular earthworks, like Lovea, a few kilometers north-west of Angkor. Burials, much richer, testify to improvement of food availability and trade (even on long distances: in the 4th century BC trade relations with India were already opened) and the existence of a social structure and labor organization.[16]
[edit] Pre-Angkorian and Angkorian polities
During the 3rd, 4th, and 5th centuries, the Indianised states of Funan and Chenla coalesced in what is now present-day Cambodia and southwestern Vietnam. These states are assumed by most scholars to have been Khmer.[17] For more than 2,000 years, Cambodia absorbed influences from India and China, passing them on to other Southeast Asian civilisations that are now Thailand, Vietnam, and Laos.[18] The Khmer Empire flourished in the area from the 9th to the 13th centuries.[19] Around the 13th century, Theravada Buddhism was introduced to the area through monks from Sri Lanka.[20]From then on, Theravada Buddhism grew and eventually became the most popular religion. The Khmer Empire declined yet remained powerful in the region until the 15th century. The empire's centre of power was Angkor, where a series of capitals was constructed during the empire's zenith. Angkor could have supported a population of up to one million people.[21] Angkor, the world's largest pre-industrial settlement complex,[22] and Angkor Wat, the most famous and best-preserved religious temple at the site, are reminders of Cambodia's past as a major regional power.
