Post-Angkor period

The post-Angkor period, also called Cambodia's Middle period, runs from the early fifteenth century, when the Khmer court left Angkor, to 1863, when Cambodia became a French protectorate. In these centuries the kingdom moved its capital south to the Mekong, traded with Asia and Europe, and was increasingly squeezed between Siam and Vietnam. Sources are scarce, especially for the fifteenth and sixteenth centuries, and much of its history is still debated.

Why the Khmer Empire declined has no single agreed answer. Temple inscriptions, the main source for earlier Khmer history, become rare in the thirteenth century and stop in the 1330s, and for some two hundred years not even a king's name survives in a contemporary record. Historians point to several changes coming together: the rise of Thai states such as Sukhothai and the Ayutthaya Kingdom, which raided Angkor according to Siamese chronicles; the turn from Hindu god-kings to Theravada Buddhism, adopted as state religion under Indravarman III; strain on Angkor's great network of canals and reservoirs; and long droughts in the fourteenth and fifteenth centuries detected by tree-ring studies. Some scholars add the pull of the growing sea trade, which favoured river ports over the inland capital. The one firm reference point is a Siamese intervention at Angkor around 1431.

The elite resettled at Chaktomuk, the site of modern Phnom Penh, where the Mekong meets the Tonle Sap river. The new capital controlled river trade with Siam and the Lao kingdoms and had access to the sea routes to China and the Indian Ocean. King Ang Chan I (1516–1566) shifted the court to Longvek, which grew into a busy trading port selling gems, silk, ivory, incense and elephants. Envoys of the Portuguese commander Afonso de Albuquerque reached Indochina in 1511, and by around 1600 Longvek hosted Chinese, Malay, Japanese, Arab, Spanish, Dutch and Portuguese traders.

In the sixteenth century Cambodia was a strong rival of Ayutthaya. After the Burmese subdued Ayutthaya in 1569, Cambodian forces besieged it in 1570 and sacked Phetchaburi in 1581, and they turned back two invasions from Lan Xang in the 1570s. Siam struck back: in 1594 its forces captured and sacked Longvek and carried Cambodian royals off to Ayutthaya. The court then moved repeatedly, to Srei Santhor, then Pursat and Lvea Aem, and finally Oudong. In 1618 King Chey Chettha II stopped paying tribute to Ayutthaya, and a Siamese attempt to reconquer the country in 1621–22 failed.

In the seventeenth century Vietnamese settlers and officials moved into the Mekong Delta, and a customs post was set up at Prey Nokor, later Saigon, in the 1620s. By the end of that century the region was under Vietnamese control, though historians such as Michael Vickery argue that this southward advance was piecemeal rather than a steady policy. In 1642 Ponhea Chan seized the throne with the help of Malay merchants, converted to Islam and ruled as Ramathipadi I; his forces defeated the Dutch East India Company in 1643–44. After Siam recovered from the Burmese sack of Ayutthaya in 1767, it took the provinces of Battambang and Siem Reap. Vietnam invaded in 1811 and, under Emperor Minh Mang, took direct control of the country in the mid-1830s, attempting to impose Vietnamese customs; the historian David Chandler called this the Vietnamisation of Cambodia. Revolts followed, and a Siamese army intervened, until a peace treaty in 1847 restored Cambodian rule under King Ang Duong.

With France annexing provinces of Cochinchina from 1861, Ang Duong secretly sought French protection to keep Cambodia from being absorbed by its neighbours. King Norodom signed the protectorate on 11 August 1863, ending the period. The delta became French Cochinchina, and Cambodia later joined French Indochina.

Our maps label this kingdom "Cambodia" from 1492 to 1815, around Phnom Penh and the lower Mekong, beside Ayutthaya and later the Rattanakosin Kingdom.