Tang Emperor of China (712–56). He came to the throne when the Tang were at their zenith. An army he dispatched to prevent the Tibetans joining with the Arabs crossed the Pamirs and reached the Hindu Kush. In 745 the emperor took as his consort Yang Guifei, formerly his son’s concubine, and began to neglect his imperial duties. In 751 the Arabs defeated the Chinese at the Talas River, resulting in the loss of earlier Tang gains in Central Asia. In 755 An Lushan, a general Yang Guifei favoured, rebelled and took Luoyang. The court fled from Chang’an, Yang was executed, and the emperor abdicated. The revolt, which dragged on until 763, was suppressed only by calling in Uighur troops from Central Asia.