Vietnamese-Laotian War (1467–80)

The Vietnamese-Laotian War of 1467–80, also known as the White Elephant War, was the biggest conflict between historical Laotian state of Lan Xang and the Vietnamese Đại Việt of Later Lê Dynasty. It was known to be the biggest and most important war that "had shaped the history of Laos" in the later years.

The war witnessed the rise of Vietnam as an imperial power and a play maker in Southeast Asia, and marked Vietnam as an undisputed power in Southeast Asia. For Laos, the war proved the incapability of Laotian Kingdom of Lan Xang on defending the country. Also, this quickly caused Lan Xang's power to seriously fade, and they were later absorbed into the Vietnamese tributary system.

Background
Ever since the Trần Dynasty, the two states didn't have good relations. Lan Xang often sent its bandits to attack Vietnamese merchants and border guards. In response, the Vietnamese interfered in Lan Xang's politics, forcing it into the orbit of Vietnam.

The Ming Dynasty's invasion led Vietnam to fall under the 4th Chinese domination. Lan Xang was the first to voice support for the Chinese domination, even sending troops to fight alongside the Chinese against Lê Lợi's Lam Sơn Uprising, but the defeat of China at 1427 had cautioned the Laotians about the vengeance of Vietnam.

In the wake of Vietnamese imperialism on the rise, Lan Xang returned to its traditional political stance, trying to play hand-to-hand, accepting to pay tribute to Vietnam, but also attacking the Vietnamese if they wanted. Beginning with the reign of Lê Thánh Tông, the Vietnamese military force quickly expanded and began adopting new weapons, in preparation for war.

1467–1477: several skirmishes
During the time, both two countries didn't declare war immediately, but instead fought some skirmishes because of the clash between Vietnamese troops and Lan Xang force. Some skirmishes ended deadly for both sides, but prior to total war, the Lan Xang had upper hand due to its pretext of using proxy army. On the other side, the Muang Phuan Kingdom had supported Lan Xang against Vietnam, and even killed Vietnamese.

The White Elephant incident: total war at 1477–78
In 1448 during the disorder of the Maha Devi, Muang Phuan and some area along the Black River became annexed by the Đại Việt and several skirmishes took place against Lan Na along the Nan River. In 1471 King Lê Thánh Tông of the Đại Việt destroyed the Kingdom of Champa. Also in 1471, Muang Phuan revolted and several Vietnamese were killed. By 1478 preparations were being made for a full-scale invasion of Lan Xang, in retribution for the rebellion in Muang Phuan and more importantly for supporting the Ming Empire in 1421.

Around the same time a white elephant had been captured and brought to King Chakkaphat. The elephant being a potent symbol of kingship was common throughout Southeast Asia, and Lê Thánh Tông requested the animal's hair to be brought as a gift to the Đại Việt court. The request was seen as an affront, and according to legend a box filled with dung was sent instead. The pretext having been set, a massive Viet force marched in five columns to subdue Muang Phuan, and was met with a Lan Xang force of 200,000 infantry and 2,000 elephant cavalry in support which was led by the crown prince and three supporting generals. it was the marking point that brought Vietnam and Laos to war.

In the wake of war, Emperor Lê Thánh Tông of Vietnam issued an invasion to Lan Xang (known as Lão Qua in Vietnamese). The Vietnamese force, which was much better prepared for war, had invaded Lan Xang at July 1478. The Laotians built up a fierce defense and fortress, but Vietnamese force, using the advance of its firearms and cannons, had quickly overrun the Lan Xang's army defense. The invasion and offensive from the Vietnamese startled the Lan Xang King Chakkaphat Phaen Phaeo that he had to flee out of Lan Xang along with entire of Royal Family from Laos. Cheo Chenglaw was captured and later, murdered by the Vietnamese. Luang Phabang was ransacked by the Vietnamese later day. The ransack of Luang Phabang was the significant point of tragedy of Lan Xang after the nation got defeated by the hand of its Eastern more powerful neighbor.

Prince Thengkham after heard the new, had organized a surprising assault in Dansai, which had caused a fierce fighting and the Vietnamese suffered heavy casualties, but even it successfully halted the Vietnamese invasion, later Vietnamese force returned in a mass number with its advance technology and firearms, soon recaptured Dan Sai.

At 1480, realizing that the Lan Xang Kingdom was no longer able to cause problem, Lê Thánh Tông ordered total retreat. On the retreat, the Vietnamese force had starved and killed majority of prisoners and people who had supported Lan Xang before.

Consequences
For Vietnam, the war highlighted what would be the greatest ever expansion of Đại Việt at the brink of history. By defeating China, and also caused the destruction of Champa, while also destroyed Lan Xang, the Vietnamese was on what would be its height of power. This was remembered as the greatest ever achievement in Vietnamese military history.

For Laos, the war had significantly weakened Lan Xang and made Lan Xang no longer capable to wage any war. While it had deteriorated the relations with Vietnam, the Laotian state of Lan Xang had to start seeking supports from the other Kingdoms in the West like Ayutthaya Kingdom. The power of Lan Xang also reduced from times and made them had no realistic power in the later future. It became highly dependent on the other powerhouses in later future, which even including Vietnam.