Angkor is one of the most important archaeological sites in South-East Asia. It contains the magnificent remains of the different capitals of the Khmer Empire, from the 9th to the 15th centuries. The influence of Khmer art, as developed at Angkor, was a profound one over much of South-East Asia and played a fundamental role in its distinctive evolution. Khmer architecture evolved largely from that of the Indian subcontinent, from which it soon became clearly distinct as it developed its own special characteristics, some independently evolved and others acquired from neighbouring cultural traditions. The result was a new artistic horizon in oriental art and architecture.
At the beginning of the 9th century the two states that covered the territory of modern Cambodia were united by Jayavarman II, who laid the foundations of the Khmer Empire, the major power in south-east Asia for some five centuries. One of the sites was in central Cambodia, to the north of Tonle Sap (Great Lake), where half a century later Jayavarman's son, Yashovarman, was to establish Yashodapura (later called Angkor), the permanent capital of the Khmer Empire until the 15th century.
The first city conformed with the classic form of Khmer capital with certain fundamental elements: a defensive bank and ditch with a state temple at its centre, built from brick or stone, and a wooden palace. There would also have been many secular buildings, constructed almost entirely of wood, in and around the enceinte. The state temple at Roluos, the Bakong, and the temple built in memory of the royal ancestors, Preah Ko, were erected around 880. Another essential feature of a Khmer capital, a large reservoir, was added a decade later, with in its centre a third temple built to the north-west of Roluos, around the hill of Phnom Bakeng, now known as the Eastern Baray.
The second capital at Angkor was built by Rajendravarman in the 960s, the state temple being situated at Pre Rup. He also constructed a temple, the Eastern Mebon, on an artificial island in the centre of the Eastern Baray. During his reign he built the exquisite temple of Banteay Srei. Rajendravarman's son, Jayavarman V, abandoned the Pre Rup site in favour of a new location with its state temple at Ta Kev, which was consecrated around 1000. Shortly afterwards he was overthrown by Suryavarman I, who was responsible for erecting the formidable fortifications around his Royal Palace and state temple, the Phimeanakas, and also for the construction of the great Western Baray.
In 1050 his successor created a new and more impressive state temple, the Baphuon. The succeeding rulers left little traces in the form of monumental buildings, and it was not until the accession of Suryavarman II in 1113 that the next great phase of building began. He was responsible for the greatest of all Khmer monuments, Angkor Vat, set within an extensive enclosure and dedicated to Vishnu. The death of Suryavarman II, around 1150, was followed by a period of internal strife and external pressure, culminating in 1177 with the sack of Angkor by the Chams. The situation was restored by Jayavarman VII, who celebrated his military success by creating yet another capital at Angkor Thorn and launching an unprecedented building campaign. His state temple was the towering Bayon, dedicated to Buddha.
Another significant element of the Angkor complex is the irrigation system of the region based on the great reservoirs, which provided the economic infrastructure for the successive Khmer capitals and their rulers.