文成公主
In 641, Li Daozong sent his daughter, who was adopted by Emperor Taizong and titled Princess Wencheng, to Tibet to be married to the Tibetan king Songtsen Gampo, as a part of the treaty of peace between Tang dynasty and Tibetan Empire. Li Daozong met Tibetan escorts at Xingxiuhai (near the Gyaring Lake and the source of Yellow River) and then returned to Chang'an.