An ancient human skull was recovered from the Tam Pa Ling Cave in the Annamite Mountains in northern Laos; the skull is at least 46,000 years old, making it the oldest modern human fossil found to date in Southeast Asia. Stone artefacts including Hoabinhian types have been found at sites dating to the Late Pleistocene in northern Laos. Archaeological evidence suggests agriculturist society developed during the 4th millennium BC. Burial jars and other kinds of sepulchers suggest a complex society in which bronze objects appeared around 1500 BC, and iron tools were known from 700 BC. The proto-historic period is characterised by contact with Chinese and Indian civilisations. According to linguistic and other historical evidence, Tai-speaking tribes migrated southwestward to the modern territories of Laos and Thailand from Guangxi sometime between the 8th–10th centuries.
Laos traces its history to the kingdom of Lan Xang (Million Elephants), founded in the 14th century, by a Lao prince Fa Ngum, who with 10,000 Khmertroops, took over Vientiane. Ngum was descended from a long line of Lao kings, tracing back to Khoun Boulom. He made Theravada Buddhism the state religion and Lan Xang prospered. Within 20 years of its formation, the kingdom expanded eastward to Champa and along the Annamite mountains in Vietnam. His ministers, unable to tolerate his ruthlessness, forced him into exile to the present-day Thai province of Nan in 1373, where he died. Fa Ngum's eldest son, Oun Heuan, came to the throne under the name Samsenthai and reigned for 43 years. During his reign, Lan Xang became an important trade centre. After his death in 1421, Lan Xang collapsed into warring factions for the next 100 years.
In 1520, Photisarath came to the throne and moved the capital from Luang Prabang to Vientiane to avoid a Burmese invasion. Setthathirat became king in 1548, after his father was killed, and ordered the construction of what would become the symbol of Laos, That Luang. Setthathirat disappeared in the mountains on his way back from a military expedition into Cambodia and Lan Xang began to rapidly decline.
It was not until 1637, when Sourigna Vongsa ascended the throne, that Lan Xang would further expand its frontiers. His reign is often regarded as Laos's golden age. When he died, leaving Lan Xang without an heir, the kingdom divided into three principalities. Between 1763 and 1769, Burmese armies overran northern Laos and annexed Luang Phrabang, while Champasak eventually came under Siamese suzerainty.
Chao Anouvong was installed as a vassal king of Vientiane by the Siamese. He encouraged a renaissance of Lao fine arts and literature and improved relations with Luang Phrabang. Under Vietnamese pressure, he rebelled against the Siamese in 1826. The rebellion failed and Vientiane was ransacked. Anouvong was taken to Bangkok as a prisoner, where he died.
A Siamese military campaign in Laos in 1876 was described by a British observer as having been "transformed into slave-hunting raids on a large scale".
French Laos (1893–1953)
In the late 19th century, Luang Prabang was ransacked by the Chinese Black Flag Army. France rescued King Oun Kham and added Luang Phrabang to the Protectorate of French Indochina. Shortly after, the Kingdom of Champasak and the territory of Vientiane were added to the protectorate. King Sisavang Vong of Luang Phrabang became ruler of a unified Laos and Vientiane once again became the capital.
Laos never had any importance for France other than as a buffer state between British-influenced Thailand and the more economically important Annam and Tonkin. During their rule, the French introduced the corvée, a system that forced every male Lao to contribute 10 days of manual labour per year to the colonial government. Laos produced tin, rubber, and coffee, but never accounted for more than one percent of French Indochina's exports. By 1940, around 600 French citizens lived in Laos.
During World War II in Laos, Vichy France, fascist Thailand, Imperial Japan, Free France, and Chinese nationalist armies occupied Laos. On 9 March 1945, a nationalist group declared Laos once more independent, with Luang Prabang as its capital but on 7 April 1945 two battalions of Japanese troops occupied the city. The Japanese attempted to force Sisavang Vong (the King of Luang Phrabang) to declare Laotian independence but on 8 April he instead simply declared an end to Laos' status as a French protectorate. The King then secretly sent Prince Kindavong to represent Laos to the Allied forces and Prince Sisavang as representative to the Japanese. When Japan surrendered, some Lao nationalists (including Prince Phetsarath) declared Laotian independence, but by early 1946, French troops had reoccupied the country and conferred limited autonomy on Laos.
During the First Indochina War, the Indochinese Communist Party formed the Pathet Laoresistance organisation. The Pathet Lao began a war against the French Colonial forces with the aid of the Vietnamese independence organisation (the Viet Minh). In 1950 the French granted Laos semi-autonomy as an "associated state" within the French Union. France remained in de facto control until 22 October 1953, when Laos gained full independence as a constitutional monarchy.
Independence and Communist Rule (1953–present)
The First Indochina War took place across French Indochina and eventually led to French defeat and the signing of a peace accord for Laos at the Geneva Conference of 1954. In 1955, the US Department of Defense created a special Programs Evaluation Office to replace French support of the Royal Lao Army against the communist Pathet Laoas part of the US containment policy.
In 1960, amidst a series of rebellions in the Kingdom of Laos, fighting broke out between the Royal Lao Army and the communist North Vietnam-backed, and Soviet Union-backed Pathet Lao guerillas. A second Provisional Government of National Unity formed by Prince Souvanna Phouma in 1962 proved to be unsuccessful, and the situation steadily deteriorated into large scale civil war between the Royal Laotian government and the Pathet Lao. The Pathet Lao were backed militarily by the NVA and Vietcong.
Laos was a key part of the Vietnam War since parts of Laos were invaded and occupied by North Vietnam for use as a supply route for its war against the South. In response, the United States initiated a bombing campaign against the North Vietnamese positions, supported regular and irregular anticommunist forces in Laos and supported South Vietnamese incursions into Laos.
In 1968 the North Vietnamese Army launched a multi-division attack to help the Pathet Lao to fight the Royal Lao Army. The attack resulted in the army largely demobilising, leaving the conflict to irregular ethnic Hmong forces of the "U.S. Secret Army" backed by the United States and Thailand, and led by General Vang Pao.
Massive aerial bombardment against the Pathet Lao and invading People's Army of Vietnamforces were carried out by the United States to prevent the collapse of the Royal Kingdom of Laos central government, and to deny the use of the Ho Chi Minh Trail to attack US forces in the Republic of Vietnam. Between 1964 and 1973, the U.S. dropped two million tons of bombs on Laos, nearly equal to the 2.1 million tons of bombs the U.S. dropped on Europe and Asia during all of World War II, making Laos the most heavily bombed country in history relative to the size of its population; The New York Times noted this was "nearly a ton for every person in Laos." Some 80 million bombs failed to explode and remain scattered throughout the country, rendering vast swathes of land impossible to cultivate and killing or maiming 50 Laotians every year. (Due to the particularly heavy impact of cluster bombsduring this war, Laos was a strong advocate of the Convention on Cluster Munitions to ban the weapons, and was host to the First Meeting of States Parties to the convention in November 2010. )
In 1975 the Pathet Lao, along with the Vietnam People's Army, and backed by the Soviet Union, overthrew the royalist Lao government, forcing King Savang Vatthana to abdicate on 2 December 1975. He later died in prison. Between 20,000 and 70,000 Laotians died during the Civil War.
On 2 December 1975, after taking control of the country, the Pathet Lao government under Kaysone Phomvihane renamed the country as the Lao People's Democratic Republic and signed agreements giving Vietnam the right to station armed forces and to appoint advisers to assist in overseeing the country. Laos was requested in 1979 by the Socialist Republic of Vietnam to end relations with the People's Republic of China, leading to isolation in trade by China, the United States, and other countries.
In addition to the North Vietnamese invasion of Laos, by the Soviet-backed Vietnam People's Army, the post-Vietnam War occupation of Laos continued during the 1970s and 1980s.
The conflict between Hmong rebels and the Vietnam People's Army of the Socialist Republic of Vietnam (SRV), as well as the SRV-backed Pathet Lao continued in key areas of Laos, including in Saysaboune Closed Military Zone, Xaisamboune Closed Military Zone near Vientiane Province and Xieng Khouang Province. From 1975 to 1996, the United States resettled some 250,000 Lao refugees from Thailand, including 130,000 Hmong.