This Cambodia history timeline traces the country from the founding of the Khmer Empire through the grandeur of Angkor, French colonization, independence, and the Khmer Rouge genocide.
The Khmer Empire and the Age of Angkor
Cambodian history is dominated for centuries by the Khmer Empire, traditionally dated to 802, when Jayavarman II declared himself a “universal monarch” and brought rival principalities under a single crown. Over the following centuries the empire’s rulers built an extraordinary sequence of temple-cities in the region around Angkor, culminating in Angkor Wat, constructed under Suryavarman II in the first half of the twelfth century as a state temple dedicated originally to the Hindu god Vishnu. At its height the empire controlled much of what is now Cambodia, Thailand, Laos, and southern Vietnam, supported by an advanced hydraulic network of reservoirs (barays) and canals that sustained intensive rice agriculture across a large population. Angkor itself grew into one of the largest pre-industrial urban settlements in the world, its temples combining Hindu and, later, Buddhist religious imagery as royal patronage shifted over successive reigns. This dominance did not last indefinitely: repeated conflict with the neighboring Siamese kingdom of Ayutthaya culminated in the sack of Angkor in 1431, after which the royal court relocated southward toward Phnom Penh, and the great temple complexes were gradually abandoned to the surrounding forest, though never entirely forgotten by local communities, who continued to maintain some shrines even as the wider city declined.
French Colonial Rule and Independence
By the nineteenth century, a weakened Cambodian monarchy faced pressure from more powerful neighbors, Siam and Vietnam, and looked to France for protection. In 1863, King Norodom signed a treaty establishing a French protectorate, and Cambodia was subsequently administered as part of French Indochina alongside Vietnam and Laos. French rule brought infrastructure and colonial administration but limited self-government, and Cambodian nationalist sentiment grew over the following decades. Independence came on November 9, 1953, achieved through the diplomatic efforts of King (later Prince) Norodom Sihanouk, who abdicated the throne in 1955 to pursue politics directly and dominated Cambodian public life for the next two decades. Sihanouk sought to keep Cambodia neutral amid the Cold War and the escalating Vietnam War, but that neutrality proved difficult to sustain as fighting in neighboring Vietnam increasingly spilled across the border. In 1970, Sihanouk was deposed in a coup led by General Lon Nol, plunging the country into a civil war that badly weakened the state and created conditions the Khmer Rouge would later exploit.
The Khmer Rouge Period, 1975–1979
Cambodia’s twentieth-century history includes one of its darkest chapters. Amid the chaos of civil war and the wider regional conflict, the communist Khmer Rouge movement, led by Pol Pot, seized the capital Phnom Penh on April 17, 1975. Over the next roughly four years the regime pursued a radical, agrarian program that emptied cities, abolished money and private property, and subjected the population to forced labor, systematic executions of perceived opponents, and starvation. Estimates of the death toll vary among scholars but are commonly placed at somewhere between 1.5 and 2 million people, a substantial share of Cambodia’s population at the time, a period widely recognized as a genocide. The regime was overthrown in January 1979 following an invasion by Vietnamese forces, though sporadic fighting between Vietnamese-backed authorities and remaining Khmer Rouge factions continued through the 1980s. A United Nations-supervised peace process led to internationally monitored elections in 1993, and Cambodia’s slow recovery from the devastation of the 1970s continued for decades afterward. Accountability came only gradually: a hybrid Cambodian-international tribunal, the Extraordinary Chambers in the Courts of Cambodia, was established in the 2000s and secured convictions of several senior Khmer Rouge leaders, though Pol Pot himself died in 1998 without ever facing trial.