First Oirat–Manchu War

The First Oirat–Manchu War was a military conflict fought from 1687-1697 between the Dzungar Khanate and an alliance of the Qing Dynasty and the Northern Yuan Dynasty. The war resulted from a Dzungar attack on the Northern Yuan, who were heavily defeated. Their rulers fled south to the Qing Dynasty, which feared a powerful Dzungar state. The Qing failed to defeat the Dzungars in an indecisive campaign, but were later able to trap the Dzungar army and defeat it at Jao Modo.

Background
After the collapse of the Yuan Dynasty, the Mongol rulers of China had withdrawn into Mongolia itself. The Mongol state disintegrated. The remnants of the Yuan formed into four semi- federated Khanates in eastern Mongolia, the senior of which was the Northern Yuan Dynasty, while the Oirat tribe constructed a powerful Khanate in western Mongolia. The Dzungars allied themselves with one of the three "junior" Khanates, but the Dzungar Khan's brother was killed in a skirmish. The powerful Khan of the Dzungars, Galdan Boshugtu Khan, was now set on war against the Northern Yuan.

War
Galdan launched an invasion of Yuan territory. The Yuan tried to check his advance, but were heavily defeated in a battle near the Erdene Zuu Monastery. Galdan occupied all of Mongolia, plundering the tombs of the old Mongol Empire at Karakoram, and turned south into Qing Manchuria. The Yuan rulers, defeated, fled to Hohhot and begged for Qing help. These two factors caused the Qing to support the Northern Yuan. A Qing-supported counterattack met the Dzungars at Olgoi Lake, but was defeated. Fearing a united Mongol state ruled by the hostile Dzungars, the Qing now turned their powerful war machine on the Oirats.

Entry of the Qing
A Qing party scouting north from the Great Wall attacked a Dzungar force, only to belatedly discover it was the main army. They were crushed. A large Qing army under the Prince Fuquan advanced North into Inner Mongolia, hoping to trap and crush the mobile Dzungars cavalry army. They were unable to do so. Running low on supplies, the Qing managed to catch them at Ulan Butung. The Dzungars formed a camel wall, beat back a pair of artillery-supported Qing assaults, and escaped into the hills. The Qing commander called it a victory, but he was dismissed into retirement. . In fact, Qing commanders were beginning to realize that nomad armies could not be defeated unless destroyed as a cohesive force.

A relatively uneventful period followed. The Northern Yuan rulers declared themselves Qing vassals at Dolon Nor (the site of Xanadu, the pleasure palace of the Yuan Emperors) a politically decisive step that officially ended the last remnants of the Yuan Dynasty. In 1696 the Qing launched 2 armies north into Mongolia. One, under the command of the Kangxi Emperor personally, was to trap and crush the Dzungars against the other army. The Dzungar army, heavily outnumbered and weakened by the plague, was unable to offer serious resistance. Galdan's army fled north, but blundered into the second army at Jao Modo. An Dzungar attack failed, and their forces broke. The Qing launched a cavalry charge, slaughtering the fleeing Dzungars. The battle ended in a victory for the Qing army, who captured 20,000 sheep and 40,000 cattle, and captured, killed or scattered all but 40-50 of the Dzungar army (although Galdan himself escaped), effectively destroying them as a military force. Galdan's wife was killed. He fled west, later attempted to surrender to the Qing, but died of the plague with only a few men in the Altai Mountains.

Aftermath
Tsewang Rabtan, an anti-Galdan Oirat chief, who had actually provided intelligence to the Qing at several points during the war, succeeded Galdan as Khan of the Dzunghars. The Qing failed to effectively curb Dzungar power, and would not until they defeated the Dzunghars in a second war some years later. A Qing garrison was put in Ulaanbaatar, and Khalka Mongolia placed under Qing rule. This provided the foundation for the incorporation of Outer Mongolia into Manchu's Qing state.