The closely related Mon and Khmer peoples entered Southeast Asia along migration routes from southern China in the ninth century B.C. The Khmer settled in the Mekong River Valley, while the Mon occupied the central plain and northern highlands of modern Thailand and large parts of Burma. Taking advantage of Funan's decline in the sixth century A.D., the Mon began to establish independent kingdoms, among them Dvaravati in the northern part of the area formerly controlled by Funan and farther north at Haripunjaya. Meanwhile the Khmer laid the foundation for their great empire of the ninth to fifteenth centuries A.D. This empire would be centered at Angkor (near modern Siem Reap) in Cambodia.