Tuyuhun

Tuyuhun was the Xianbei kingdom of Qinghai from 285 to 663, the first nomad state on the Tibetan plateau's edge. Murong Tuyuhun, younger son of a Liaodong chief, quarrelled with his elder brother over a horse in 285 and rode west with seven hundred tents to the lakes of Qinghai, where his people, Xianbei speaking a Mongolic tongue, mixed with Qiang and Tibetans. His house called its realm Henan, south of the river, and Tang histories called its kings Henan Wang. The Tuyuhun grew rich taxing the Silk Road's southern branch and strong enough to raid Gansu; Taizong answered with marriage, sending Princess Honghua to the khan, and with armies when tribute lapsed. Caught between Tang and the rising Tibetans, the khans played both: Nuohebo, the last effective khan, married another Tang princess and begged Chang'an for rescue year after year. In 663 Songtsen Gampo's generals overran Fuqi, the lake capital; Nuohebo fled east with the court to Tang protection, and his house lived on as Tang generals and prefects while Tibet swallowed the pastures. The plateau's first kingdom thus became the Tang's western shield in exile.