The Khmer Empire, now known as Cambodia, was the powerful Khmer Hindu-Buddhist empire in Southeast Asia. The empire, which grew out of the former kingdom of Chenla, at times ruled over and/or vassalized most of mainland Southeast Asia, parts of modern-day Laos, Thailand, and southern Vietnam.
Its greatest legacy is Angkor, in present-day Cambodia, which was the site of the capital city during the empire's zenith. The majestic monuments of Angkor — such as Angkor Wat and Bayon — bears testimony to the Khmer empire's immense power and wealth, impressive art and culture, architectural technique and aesthetics achievements, as well as the variety of belief systems that it patronised over time. Recently satellite imaging has revealed Angkor to be the largest pre-industrial urban center in the world.
The beginning of the era of the Khmer Empire is conventionally dated to 802 AD. In this year, king Jayavarman II had himself declared chakravartin ("king of the world", or "king of kings") on Phnom Kulen. The empire ended with the fall of Angkor in 14th century.