The Khmer empire was the largest continuous empire of South East Asia, based in what is now Cambodia. The empire, which seceded from the kingdom of Chenla, at times ruled over or vassalised parts of modern-day Laos, Thailand and Vietnam. During the formation of the empire, the empire had intensive cultural, political, and trade relations with Java, and later with the Srivijaya empire that lay beyond the Khmer state's southern border. Its greatest legacy is Angkor, which was the capital during the empire's zenith. Angkor bears testimony to the Khmer empire's immense power and wealth, and the variety of belief systems that it patronised over time. The empire's official religions included Hinduism and Mahayana Buddhism, until Theravada Buddhism prevailed after its introduction from Sri Lanka in the 13th century. Satellite imaging reveals Angkor to have been the largest pre-industrial urban center in the world, larger than modern-day New York.
