How a Palace Coup Invited the Uyghur Khaganate's Destruction

The Challenge

By the 830s the Uyghur Khaganate, for nearly a century the leading power of the Mongolian steppe, was weakened by court factions. In 832 one qaghan was murdered by his own followers. Then, in 839, famine, epidemic and a severe winter killed much of the livestock on which the economy depended.

The Approach

• The minister Qasar forced Zhangxin Qaghan to commit suicide in 839 and took the throne himself
• He relied on 20,000 Shatuo horsemen from the Ordos to make the coup succeed
• He did not win over his rivals among the khaganate's ministers; one of them, Külüg Bagha, fled to the Yenisei Kyrgyz and invited them to invade

The Impact

In 840 about 80,000 Kyrgyz horsemen sacked and razed the Uyghur capital, Ordu-Baliq, and executed Qasar. The khaganate collapsed on the steppe.

The Uyghurs scattered: some to the Chinese frontier, where the Tang refused them and later turned on them, others southwest to found new kingdoms at Gaochang and in Gansu.

The Lesson for Leaders

A leadership fight during a crisis hands opponents the opening they need. Qasar won the throne but left a rival with nothing to lose, and that rival brought in an outside power that destroyed everything. Seizing control is not the same as securing it.