The Khmer from origins times
If one is to believe the legend, the ancient dynasties of the Khmer empire were derived from the union of a Hindu prince, Prah Thong who had been banished from Delhi by his father with a "female serpent-woman", the daughter of the Nakaraja, who was sovereign of the land. She appeared to him in radiant beauty, frolicking on a sand bank where he had come to make camp for the night. He looks her as his wife, and the Nakaraja, draining the land by drinking the water that covered it, gave him the new country, called it Kambuja and build him a capital.
A variation, revealed on an inscription at Mison in Champa (mid Vietnam) and reproduced in various descriptions of Cambodia, substitutes for the prince the Brahman Kaundinya, who "married the nagi Soma to accomplish the rites" and throwing the magic lance with which he was armed, founded at the point of its landing the royal city where Somavamsa, the race of the moon, would rule.
Another popular tradition, though less widespread, gives as the origin the coupling of the maharachi Kambu and the apsara Mera, whose union of symbolic of the between the two great race, solar(Suryavamsa) and lunar (Somavamsa). This survives particularly in the word Kambuja-son of Kambu from where derives the name "Cambodian" by which were now call the present descendants of the ancient Khmer.
Whichever version one takes, the mythical implication is undeniable and the truth remains that the Khmer people are born of a joining of two distinct elements; Indian and Native. They are not as some would believe, just people of purely Indian or Hindu origin who had come, following migration, to settle in a region devoid of any inhabitants, or where the indigenous race had been eliminated by mass deportation.