Thai chronicle traditions describe a siege of Angkor Thom of some seven months ending with the city's capture by Ayutthaya, conventionally dated to 1431, after which the Khmer king was killed or fled and an Ayutthayan prince was installed. The same chronicles say the victors removed the Khmer royal family, Brahman ritual specialists, court dancers, artisans and a mass of ordinary people to Ayutthaya, a practice consistent with the wider Southeast Asian pattern in which war was fought for manpower rather than territory, and Khmer court culture is generally held to have entered Siamese royal practice through this transfer. The Khmer political centre subsequently shifted to the Phnom Penh and later Longvek region, though the reasons - military pressure, trade, hydraulic decline - are debated. Modern scholarship, particularly Michael Vickery's, treats the chronicle accounts as late and unreliable, questions the 1431 date, and rejects the older narrative of a sudden and total abandonment of Angkor; archaeological work shows continued occupation of the Angkor region for generations afterwards. The episode is included here for the deportation of population it is recorded as involving, while noting that its scale cannot be established.
The Ayutthaya kingdom captured the Khmer capital and, by Thai chronicle accounts, carried off its court, artisans and population
Klassen, Evans and colleagues' 2021 demographic model, built from airborne laser scanning of the Angkor region and mound-density analysis, puts Greater Angkor at roughly 700,000-900,000 people at its peak in the thirteenth century, with the walled civic-ceremonial core holding on the order of 20,000-25,000. Angkor's population in the 1430s was substantially lower after decades of hydraulic decline and political contraction, but the size of that decline is not quantified, so this baseline is a peak figure and not a 1431 figure.
No figures exist. The chronicles record a long siege and the killing of the Khmer king, but give no toll, and no independent evidence bears on mortality.
Thai chronicle traditions describe a siege of several months before the city fell; no other form is documented by an identifiable source.
Cambodia, Thailand