Qasar Qaghan

Overview

Qasar Qaghan was the minister who seized the Uyghur throne in 839 and the ruler under whom the khaganate fell. His coup, backed by foreign cavalry, split the court at the worst possible moment. A rival minister invited the Yenisei Kyrgyz to invade, and in 840 they sacked the Uyghur capital, Ordu-Baliq, and executed him.

Rise to Power

Qasar, one of the khaganate's ministers, forced Zhangxin Qaghan to commit suicide in 839 and took the throne with the support of 20,000 Shatuo horsemen from the Ordos.

Rule and Achievements

• Took power by coup in 839, in a year of famine, epidemic and mass livestock deaths
• Was opposed by Külüg Bagha, one of the nine Uyghur ministers, who fled to the Yenisei Kyrgyz and invited them to attack
• Lost his capital in 840, when about 80,000 Kyrgyz horsemen sacked and razed Ordu-Baliq and destroyed other Uyghur cities
• Was captured and executed by the Kyrgyz, ending the Uyghur Khaganate's rule over the Mongolian steppe

Legacy

Qasar Qaghan's short reign is the clearest case in steppe history of a leadership struggle inviting outside destruction. He won the throne by force, but the rival he failed to win over brought in an enemy that destroyed everything. The Uyghurs scattered: some to the Tang frontier, others southwest to found new kingdoms at Gaochang and in Gansu that lasted for centuries.