Ligdan Khan
The Oirats had established peace with the Khalkha Mongols since Ligdan Khan died in 1634 and the Khalkhas were preoccupied with the rise of the Qing dynasty. However, when the Jasaghtu Khan Shira lost part of his subjects to the Tüsheet Khan Chikhundorj, Galdan moved his orda near the Altai Mountains to prepare an attack. Chikhundorj attacked the right wing of the Khalkhas and killed Shira in 1687. In 1688, Galdan dispatched troops under his younger brother Dorji-jav against Chikhundorj but they were eventually defeated. Dorji-jav was killed in battle. Chikhundorj then murdered Degdeehei Mergen Ahai of the Jasaghtu Khan who was on the way to Galdan. To avenge the death of his brother, Galdan established friendly relations with the Russians who were already at war with Chikhundorj over territories near Lake Baikal. Armed with Russian firearms, Galdan led 30,000 Dzungar troops into Khalkha Mongolia in 1688 and defeated Chikhundorj in three days. The Siberian Cossacks, meanwhile, attacked and defeated a Khalkha army of 10,000 near Lake Baikal. After two bloody battles with the Dzungars near Erdene Zuu Monastery and Tomor, Chakhundorji and his brother Jebtsundamba Khutuktu Zanabazar fled across the Gobi Desert to the Qing dynasty and submitted to the Kangxi Emperor.