Songtsen Gampo builds the Tibetan Empire

Songtsen Gampo inherited from his father Namri Songtsen a kingdom built by the clans of the Yarlung valley. Tibetan tradition says that he came to the throne at the age of thirteen, after his father had been poisoned, while the Old Book of Tang says he succeeded at about twenty; his accession is dated to 618 or to 629. He extended his rule over the plateau — according to the Old Book of Tang, the neighbouring Yangtong (Zhangzhung) and the Qiang tribes submitted to him — and moved his seat from the Yarlung valley to Rasa, the future Lhasa.

His first embassy reached the Tang court in 634. When he was refused a princess and his envoy blamed the intrigues of the Tuyuhun, he attacked them, and they fled to the shores of Kokonor; then he subdued the Dangxiang and other Qiang and, according to the Chinese histories, camped with more than 200,000 men on the western border of Songzhou, sending word that he had come to fetch his bride. In the autumn of 638 a surprise attack by Niu Jinda drove his army from the walls of the town; Songtsen withdrew, apologised and asked again, and at the end of 640 his minister Gar Tongtsen brought 5,000 taels of gold and hundreds of treasures to the Tang court. In 641 Taizong sent Princess Wencheng, of a minor branch of the imperial clan, with Li Daozong as her escort. The Old Book of Tang says that Songtsen met her at the source of the Yellow River, built a walled town and a palace for her, gave up felt and furs for silk and sent sons of his nobles to study in the Tang capital; as John Powers notes, Tibetan histories do not corroborate this picture of a king won over to Chinese ways.

In 648 Tibetan troops helped the Tang envoy Wang Xuance against a usurper in northern India, and after Taizong’s death Gaozong made Songtsen an imperial son-in-law and Prince of Xihai; Songtsen asked him for silkworm eggs and for craftsmen to make wine, mills, paper and ink. He died in 649 according to the Old Tibetan Annals, in 650 according to the Chinese histories, leaving the throne to a young grandson and power to Gar Tongtsen, under whose family Tibet crushed the Tuyuhun in 663 and in 670 overran the Tang garrisons of the Tarim Basin. Tradition credits Songtsen with the Tibetan script, attributed to his minister Thonmi Sambhota, and with the first Buddhist temples of Lhasa, built for images brought by his Nepali and Chinese wives. An inscription of the early 9th century already says that the temple of Rasa was built in his reign, but much else in the tradition is later legend.