The Khmer Empire was a Hindu-Buddhist empire in Southeast Asia, centered around hydraulic cities in what is now northern Cambodia. Known as Kambuja by its inhabitants, it grew out of the former civilisation of Chenla and lasted from 802 to 1431. Historians call this period of Cambodian history the Angkor period, after the empire's most well-known capital, Angkor. The Khmer Empire ruled or vassalised most of mainland Southeast Asia and stretched as far north as southern China. At its peak, the Empire was larger than the Byzantine Empire, which existed around the same time.

Angkor, also known as Yasodharapura, was the capital city of the Khmer Empire. The city and empire flourished from approximately the 9th to the 15th centuries. The city houses the Angkor Wat, one of Cambodia's most popular tourist attractions.