Jayavarman II, when as a prince, was being held as a Chenla hostage to the Java court. Getting a chance to return to his motherland, he vigorously pursued for powers and became the king in 790 A.D. For the next 12 years, he carried out many battles around the regions and tried to seek a perfect home for his own kingdom.
When Jayavarman II became stronger, he decided to establish his capital Hariharala in the region of Roluos on the plain northwest of Tonle Sap.
In 802, Jayavarman II crowned himself for the second time, which marked as a starting point of the Khmer Civilization and the birth of the Angkor Empire. He made a breakthrough by proclaiming 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, a supreme Hindu deity, who was known by the Khmer for a long time as a god of protector. Being revered as a god-king, King Jayavarman II had psychologically asserted his divine kingship over the Khmer of his absolute authority and sovereignty. Moreover, it implied the declaration of Independence from Java Empire.
Adopting the Indian concept of divine kingship was proven to be a very clever strategy and served as a strong root for the steady growth of the Angkor Civilization. A rational reason as of why Jayavarman II adopted this concept could have lie in the fact that the Indian civilization had already been set as a successful example in Indian subcontinent. Every monarch or deva-raja from Jayavarman II onwards was highly revered with divine loyalty. The nation was strongly unified and later evolved into an empire.
Moreover, Jayavarman II did not select the location of his capital at random. He considered its strategic location in term of military. At that time, his potential enemies were in the south and in the east. Situated inland with thick rugged forests, his kingdom could be accessed only through river tributary of Tonle Sap lake. Being at the north of the lake, it meant that his force was at the river upstream which was an added advantage. This also had proved to be a right strategy for the existence of the Angkor Empire for over 600 years as it lost only one major naval battle against Champa in 1177.
After the establishment of Angkor kingdom, Jayavarman II actively waged wars throughout Cambodia and expanded his territory. He built a temple devoted to god Shiva at Phnom Kulen about 40 km northwest of Tonle Sap. King Jayavarman II reigned until 834 A.D.; "Jaya" literally means "victorious" and "varman" - "the protector".