Who was Galdan Boshigt Khan, and why did Kangxi fight him?

Galdan Boshigt Khan (reigned 1676–1697) was a powerful leader of the Dzungar tribes of Mongols. Originally educated as a Buddhist lama in Tibet, he returned to Central Asia to avenge his brother’s murder, subsequently building an empire that spanned from East Turkistan to Outer Mongolia.1

The Kangxi emperor fought Galdan primarily because of the threat Galdan’s expansionist ambitions posed to the stability of the Qing dynasty. Galdan’s invasion of the Khalkha Mongols forced them to flee into Inner Mongolia to seek protection under the Qing, effectively bringing the conflict to the empire's borders. Furthermore, Galdan led his armies toward Beijing in 1690, directly challenging the Qing capital.21

Kangxi viewed the Dzungar threat as a menace to imperial security and sought to protect the Khalkha tribes, who had pledged their allegiance to him at Doloon Nuur. The conflict culminated in 1696 when Kangxi personally led a military expedition across the Gobi and defeated Galdan at Dzuunmod, ultimately securing Outer Mongolia as part of the Qing empire.21