Uyghur Khaganate - Golden Age

Golden Age

During the reign of Tengri Bögü the Uyghurs reached its height of power. In 762, with the help of Tengri Bögü, the Tang Emperor Daizong finally quelled the An Lushan rebellion (then under the leadership of Shi Chaoyi) and the eastern capital Luoyang was recaptured. Treaty of Peace and Alliance was concluded with Tang, which had obligation to pay 40 rolls of silk to Uyghur Empire in exchange for every horse brought by the Uyghurs, also Uyghurs who were living in Tang China all were considered as " guests " and freed from payment any taxes and accommodation costs.

Khagan Tengri Bögü met with Manichaean priests from Iran while on campaign, and was converted to Manicheism, adopting it as the official religion of the Uyghur Empire in 763. One effect of this conversion was the increase in influence of the Sogdians in the Uyghur court. In 779 Tengri Bögü, incited by his Sogdian advisers, planned an invasion of China to take advantage of the accession of a new Emperor Dezong. However, Tengri Bögü's uncle, Tun Bagha Tarkhan, opposed this plan:

Tun Bagha became annoyed and attacked and killed him and, at the same time, massacred nearly two thousand people from among the kaghan's family, his clique and the Sogdians.

The rebellion supposedly was sponsored by Tang Ambassador in Uyghur Empire. Tun Bagha Tarkhan ascended the throne with title Alp Qutlugh Bilge ("Victorious, glorious, wise") and enforced a new set of laws, which he designed to secure the unity of the khaganate, He also moved against the Kyrgyz once more, finally bringing them under the Uyghur Khaganate's control.