Reconstructing Angkor's royal succession has required over thirty years of work by Orientalists. 27 kings are known to have ruled between 802 and 1327. Beyond that date, no more writings can be found. A few linguistic remarks might be useful. For instance, the suffix "Varman" -often ending Kings' names- means "armour" in Sanskrit and "Jaya" can be translated as "victory".
Jayavarman II was the first king to settle in the Roluos area -15 km from Siem Reap on the road to Phnom Penh. What is known as "Angkorian history" is commonly accepted to have started in 802, the year he was sacred "Universal Monarch" ("Chacravartin" in Sanskrit), on mount Mahendra, on Phnom Kulen. Although he declared himself "King of Kings" he only ruled one kingdom among many others, all as independent as his own. However, it is Jayavarman II who introduced the concept of the cult of the God-King -or Devaraja- starting a tradition that was to last to the present day. Followers believed the King was the earthly representative of one of the gods and ancient Khmer inscriptions mention "The Lord of the Universe who is King". Jayavarman II is said to have become the first Devaraja at a ceremony on Phnom Kulen. This transition from man to God-King enabled him and successive rulers to unify the Khmer Empire and establish themselves at its head, as well as bestowing upon them the responsibility to ensure the security and welfare of the Khmer nation. The main symbol of the Devaraja is that of the Linga, a phallus-shaped object representing the creative energies and powers of nature. Little is known about the reign of Jayavarman II the first Devaraja, as no inscriptions written during his reign have been found. The prince had to re-conquer his kingdom before being able to proclaim himself God-King. His son Jayvarman III succeeded him. The fact that we know very little of Jayavarman III's reign is regarded by some scholars as an indication that the period was probably peaceful. Jayvarman III (830-877) and his nephew Indravarman (877-886) remained in Hariharalaya. Indravarman is thought to have been a powerful king and is credited with expanding the size and importance of the Roluos group, the first classical Angkorian city. Between 879 and 881 he built Preah Ko and the temple-mountain of Bakong.