Historians continue to put the pieces of The Mekong’s puzzling past together. Archaeological evidence suggests that Luang Prabang has been inhabited since 8,000 BC. The earliest recorded civilization on the Mekong is the 1st century Indian-Khmer culture of Funan in the Delta area. The Khmer culture was evolving into the Chenla Kingdom during this period, which included today’s Vat Phou UNESCO World Heritage Site in Champasak. There is also plenty of physical evidence revealing that the ethnic Khmu began settling in the Golden Triangle at this time.  

Around the 6th century, King Mahendravarman established the City of Shrestapura on the Lower Mekong as the centre of the Khmer Kingdom, and construction of Vat Phou began. The city lost its status as the Khmer capital in the 8th century to Angkor Wat, but continued to flourish as a major satellite of the empire. Vientiane was settled in the 9th century.

Though evidence is imprecise, historians believe a civilization was established during the same period in the Golden Triangle, most likely by Tai migrating from south-western China. The capital and trade hub, Souvannakhomkham, was founded on the Lao side of the Mekong, and the ensuing empire stretched to Vietnam through the 11th century. The Tai then shifted their capital across the Mekong to Chiang Saen, Thailand, after Souvannakhomkham “disintegrated into swamp”.

Some historians believe the move marked the establishment of the Lanna Kingdom in Northern Thailand.

Meanwhile, the Khmer Empire was in decline, and the Lower Mekong in Laos became torn between the emerging kingdoms of Siam and Tonkin (northern Vietnam) by the 12th century.

The first Laos kingdom, Lane Xang, was founded in Luang Prabang on the Mekong in the 14th century by King Fa Ngum, who conquered and unified the lands around the kingdom’s capital, Xieng Khouang Province, and the Korat Plateau in north-eastern Thailand. By 1545, the Lane Xang Kingdom took control of the Souvannakhomkham area. It is believed that most of the ruins visible today, date from this era.

However, Lane Xang influence over the area was short lived, as invading Burmese pushed the kingdom’s reach back to Luang Prang. With pressure building over control of the upriver stretches of the Mekong, King Setthathirath moved the capital to Vientiane in 1563, to avoid the invading Burmese.

A couple of decades earlier, in 1540, Portuguese explorer Antonio de Faria became the first European to sail into the Mekong at the river’s delta. A century later, Dutchman Gerrit van Wuysthoff led a 2-year Mekong expedition to Vientiane, arriving in 1642. When Lane Xang collapsed in 1707, Vientiane became an independent kingdom.

French explorers Ernest Doudard de Lagrée and Francis Garnier led a Mekong expedition from Saigon to Yunnan from 1866-1868, and decided the river had little navigational use, due to it many falls and rapids in Champasak Province. By this time British and French colonials had established a presence in Indochina. The Burmese fell under British control, while the French held sway over Laos, Vietnam, and Cambodia, all of which share the Mekong.

The British failed to colonize Siam, which was pushing across the Mekong into Lao ports in the late 19th century. In defence of Laos, France waged a naval battle with Siam on the Chao Phaya River near Bangkok in 1896. The British did not come to Siam’s defence. After the battle, the Siamese ceded Laos and the Mekong to France. France then signed a treaty with Britain stipulating that the Mekong was the border between Laos and British territory in Upper Burma. The French now ruled the Mekong downriver from China.

The French tried again to find a way to sail all the way up The Mekong with the goal of reaching “Shangri-La” in western Yunnan. After repeated failures in finding a way up the Mekong’s turbulent waters in Champasak, they erected a hoist and railway system on Don Khone and Don Det to bypass the obstacle and continue up river. Pyotr Kuzmich Kozlov discovered the river’s source in the Tibetan Plateau in 1900. The Indochina Wars expelled the French and the US, and the former Indochina colonies and Thailand regained control of the Mekong.