Abandonment of Angkor

Timeline

1. c. 1430–1431Angkor Thom · Siem Reap ProvinceAyutthaya's King Borommaracha II launched an offensive against the Khmer capital. Siamese chronicles say the siege of Angkor Thom lasted months before the city fell, with people and sacred images carried off. This blow made Angkor's position as a defensive core untenable.
2. 1431–1433Basan (Sresantok) · Kampong ChamPonhea Yat judged Angkor indefensible against repeated Siamese attacks, gave up Angkor as capital, and led the court south to Basan (Sresantok) on the Mekong. Angkor lost its main administrative function but retained residents and Buddhist temple activity.
3. c. 1432–1434Four Arms (Chaktomuk) · Phnom PenhAfter floods in the Basan area, the royal court moved again to the Four Arms at the confluence of the Mekong and Tonlé Sap, the precursor of later Phnom Penh. The Khmer political center shifted from an inland hydraulic capital to a river port, ending Angkor's phase as capital of a unified empire.