The period of Angkor is the period in the history of the Khmer Empire from approximately the latter half of the 8th century AD to the first half of the 15th century CE.
In any study of Angkorian architecture, the emphasis is necessarily on religious architecture, since all the remaining Angkorian buildings are religious in nature. During the period of Angkor, only temples and other religious buildings were constructed of stone. Non-religious buildings such as dwellings were constructed of perishable materials such as wood, and so have not survived.
The religious architecture of Angkor has characteristic structures, elements, and motifs, which are identified in the glossary below. Since a number of different architectural styles succeeded one another during the Angkorean period, not all of these features were equally in evidence throughout the period. Indeed, scholars have referred to the presence or absence of such features as one source of evidence for dating the remains.
Many temples had been built before Cambodia became a powerful Kingdom of Khmer Empire which dominated most of the Indochina region. At that time, Cambodia was known as Chenla kingdom, the predecessor state of Khmer empire. There are three pre-Angkorean architectural styles :
Scholars have worked to develop a periodization of Angkorean architectural styles. The following periods and styles may be distinguished. Each is named for a particular temple regarded as paradigmatic for the style.
Angkorian builders used brick, sandstone, laterite and wood as their materials. The ruins that remain are of brick, sandstone and laterite, the wood elements having been lost to decay and other destructive processes.
The earliest Angkorian temples were made mainly of brick. Good examples are the temple towers of Preah Ko, Lolei and Bakong at Hariharalaya. Decorations were usually carved into a stucco applied to the brick, rather than into the brick itself.
Angkor's neighbor state of Champa was also the home to numerous brick temples that are similar in style to those of Angkor. The most extensive ruins are at Mỹ Sơn in Vietnam. A Cham story tells of the time that the two countries settled an armed conflict by means of a tower-building contest proposed by the Cham King Po Klaung Garai. While the Khmer built a standard brick tower, Po Klaung Garai directed his people to build an impressive replica of paper and wood. In the end, the Cham replica was more impressive than the real brick tower of the Khmer, and the Cham won the contest.