A later inscription dates the empire's founding to 802, when Jayavarman II had a brahmin perform a rite on the Kulen hills that established him as universal monarch and instituted the cult usually called devaraja. What the term meant is still argued: an older reading made the king a living god, while more recent scholarship reads it as the cult of a divine protector of kingship rather than the deification of the man. Either way the consecrated ruler and the state cult were bound together, and every strong king marked his reign by building.
They built in a form borrowed from Indian cosmology and made monumental: the temple mountain, a stepped pyramid standing for Mount Meru, surrounded by a moat standing for the encircling ocean. The greatest of them, Angkor Wat, was raised by Suryavarman II from about 1113 as a temple to Vishnu, unusually oriented to the west, its galleries carrying nearly two thousand apsara figures and a bas-relief of the churning of the ocean of milk more than forty metres long. It remains the largest religious structure ever built.
Around the temples lay a landscape of vast reservoirs, the barays, and canals. Whether these were primarily irrigation works supporting a hydraulic state or ritual constructions modelling the cosmic ocean was argued for decades; Charles Higham's survey concludes, with the aerial and excavation evidence, that they were both at once.