So, who are the Khmers anyway?

It's an interesting question. Who are the Khmers and how do they relate to the rest of Indochina?

We don't really know who populated the Cambodian territory in early prehistory, but it was probably a mixture of Sino-Tibetan people much like those who populated most of Indochina. In addition there might have been some Austronesian people, much like the proto-Malays who populated other parts of South East Asia and Peninsular Malaya. But what makes Cambodia somewhat distinct is that the earliest recorded civilization was an Indianized civilization called Funan about 2000-2500 years ago. The Indianization apparently occured as a result of infiltration by a group of Kambujas from North Western India. These Kambujas probably intermarried with locals and subsequently assimilated into the local population and gave rise to what we now recognize as the Khmer ethnic group. The Cambodian royalty apparently still take some pride in tracing their lineage back to the Indian Kambujas.

So what we have now in Cambodia is a largely Khmer population who are principally Indianized Sino-Tibetan people, plus some Austronesians (Champas) and relatively more recent Chinese immigrants. Because the Khmer influence was so dominant during the Angkor civilization, it is likely that the Indianized Khmer ethnic traits spilled over into the North Eastern Thai populations. (See 'So, who are the Thais anyway?')