Cambodia is a country with a rich and complex history that spans many centuries. From the ancient kingdoms of Funan and Chenla to the glorious era of Angkor and beyond, Cambodia has witnessed the rise and fall of civilizations, the influence of foreign powers, and the struggle for independence and democracy.

1. Pre - history:

There exists sparse evidence for a Pleistocene human occupation of present-day Cambodia, which includes quartz and quartzite pebble tools found in terraces along the Mekong River, in Stung Treng and Kratié provinces, and in Kampot Province, although their dating is unreliable. Some slight archaeological evidence shows communities of hunter-gatherers inhabited the region during Holocene: the most ancient archaeological discovery site in Cambodia is considered to be the cave of Laang Spean, in Battambang Province, which belongs to the Hoabinhian period. Excavations in its lower layers produced a series of radiocarbon dates around 6000 BC. Upper layers in the same site gave evidence of transition to Neolithic, containing the earliest dated earthenware ceramics in Cambodia.

Archaeological records for the period between Holocene and Iron Age remain equally limited. A pivotal event in Cambodian prehistory was the slow penetration of the first rice farmers from the north, which began in the late third millennium BC. The most curious prehistoric evidence in Cambodia are the various "circular earthworks" discovered in the red soils near Memot and in the adjacent region of Vietnam in the latter 1950s. Their function and age are still debated, but some of them possibly date from second millennium BC.

2. Pre-Angkorian and Angkorian era:

During the 3rd, 4th, and 5th centuries, the Indianised states of Funan and its successor, Chenla, coalesced in present-day Cambodia and southwestern Vietnam. For more than 2,000 years, what was to become Cambodia absorbed influences from India, passing them on to other Southeast Asian civilisations that are now Thailand and Laos. Little else is known for certain of these polities, however Chinese chronicles and tribute records do make mention of them. It is believed that the territory of Funan may have held the port known to Alexandrian geographer Claudius Ptolemy as "Kattigara". The Chinese chronicles suggest that after Jayavarman I of Chenla died around 681, turmoil ensued which resulted in the division of the kingdom into Land Chenla and Water Chenla which was loosely ruled by weak princes under the dominion of Java.

The Khmer Empire grew out of these remnants of Chenla, becoming firmly established in 802 when Jayavarman II (reigned c. 790 – c. 835) declared independence from Java and proclaimed himself a Devaraja. He and his followers instituted the cult of the God-king and began a series of conquests that formed an empire which flourished in the area from the 9th to the 15th centuries. During the rule of Jayavarman VIII the Angkor empire was attacked by the Mongol army of Kublai Khan, however, the king was able to buy peace. Around the 13th century, Theravavada missionaries from Sri Lanka reintroduced Theravada Buddhism to Southeast Asia; having sent missionaries previously in 1190s. The religion spread and eventually displaced Hinduism and Mahayana Buddhism as the popular religion of Angkor; however it was not the official state religion until 1295 when Indravarman III took power.

The Khmer Empire was Southeast Asia's largest empire during the 12th century. The empire's centre of power was Angkor, where a series of capitals were constructed during the empire's zenith. In 2007 an international team of researchers using satellite photographs and other modern techniques concluded that Angkor had been the largest pre-industrial city in the world with an urban sprawl of 2,980 square kilometres (1,151 square miles). The city, which could have supported a population of up to one million people and Angkor Wat, the best known and best-preserved religious temple at the site, still serves as a reminder of Cambodia's past as a major regional power. The empire, though in decline, remained a significant force in the region until its fall in the 15th century.

3. Post-Angkor Period:

After a long series of wars with neighbouring kingdoms, Angkor was sacked by the Ayutthaya Kingdom and abandoned in 1432 because of ecological failure and infrastructure breakdown. This led to a period of economic, social, and cultural stagnation when the kingdom's internal affairs came increasingly under the control of its neighbours. By this time, the Khmer penchant for monument building had ceased. Older faiths such as Mahayana Buddhism and the Hindu cult of the god-king had been supplanted by Theravada Buddhism.

The court moved the capital to Longvek where the kingdom sought to regain its glory through maritime trade. The first mention of Cambodia in European documents was in 1511 by the Portuguese. Portuguese travellers described the city as a place of flourishing wealth and foreign trade. Continued wars with Ayutthaya and the Vietnamese resulted in the loss of more territory and Longvek being conquered and destroyed by King Naresuan the Great of Ayutthaya in 1594. A new Khmer capital was established at Oudong south of Longvek in 1618, but its monarchs could survive only by entering into what amounted to alternating vassal relationships with the Siamese and Vietnamese for the next three centuries with only a few short-lived periods of relative independence.

In the nineteenth century, a renewed struggle between Siam and Vietnam for control of Cambodia resulted in a period when Cambodia became the Tây Thành Province of Nguyễn Vietnam, during which Vietnamese officials attempted to force the Khmers to adopt Vietnamese customs. This led to several rebellions against the Vietnamese and appeals to Thailand for assistance. The Siamese–Vietnamese War (1841–1845) ended with an agreement to place the country under joint suzerainty. This later led to the signing of a treaty for French Protection of Cambodia by King Norodom Prohmborirak.

4. French colonisation:

In 1863, King Norodom, who had been installed by Siam, sought the protection of Cambodia from Siam by French rule. In 1867, Rama IV signed a treaty with France, renouncing suzerainty over Cambodia in exchange for the control of Battambang and Siem Reap provinces which officially became part of Siam. The provinces were ceded back to Cambodia by a border treaty between France and Siam in 1907.

Cambodia continued as a protectorate of France from 1867 to 1953, administered as part of the colony of French Indochina, though occupied by the Japanese empire from 1941 to 1945 and briefly existing as the puppet state of Kingdom of Kampuchea in mid-1945. Between 1874 and 1962, the total population increased from about 946,000 to 5.7 million. After King Norodom's death in 1904, France manipulated the choice of king, and Sisowath, Norodom's brother, was placed on the throne. The throne became vacant in 1941 with the death of Monivong, Sisowath's son, and France passed over Monivong's son, Monireth, feeling he was too independently minded. Instead, Norodom Sihanouk, a maternal grandson of King Sisowath was enthroned. The French thought young Sihanouk would be easy to control. They were wrong, however, and under the reign of King Norodom Sihanouk, Cambodia gained independence from France on 9 November 1953.