The earliest known settlements were built to the west of the plain, but the Angkorian period as such began when king Jayavarman II returned from Java at the beginning of the 9th century, unified the country and settled at Hariharalaya or Roluos to the east. He then moved north to the Kulen hills, where he introduced the cult of the God King.   Returning again to the plain, he died at Hariharalaya in 850. This area was adopted by his son and then his nephew, Indravarman I, who built Bakong, the first major sandstone temple-pyramid. The temple mountain was symbolic of Mount Meru of Hindu mythology - the five tiered mountain at the centre of the universe (the temple) was said to be encircled by seven chains of mountains (the enclosure walls) which were surrounded in turn by the sea (the moats).