Relations between
China and Tibet began to sour during this reign as he began to expand into the Tang territory. In 658, Mangsong "again" sent presents to
Emperor Gaozong asking for a princess to marry, but this request was refused. He then consolidated Tibet's hold over the whole of the Tibetan plateau controlling both the
Azha in the east and
Zhang Zhung in the west. However, by 658 China had gained control of both
Khotan and
Kucha and established protectorates as far as
Sogdia and
Kashmir. Sometime prior to 662, Mangsong had allied himself with the
Western Turks and together they began raiding the Chinese protectorates. They attacked
Kashgar in 663, and
Khotan in 665. In 667, the Turkic
Nushibi of the Onoq submitted to Tibet, which also controlled the strategic
Wakhan valley. Between 665 and 670,
Khotan was defeated by the Tibetans, and a long string of conflicts ensued with China. In the spring of 670, Tibet
attacked the remaining Chinese territories in the western
Tarim Basin. With troops from Khotan they conquered
Aksu, upon which the Chinese abandoned the region, ending two decades of Chinese control. They thus gained control over all of the Chinese
Four Garrisons of Anxi in the
Tarim Basin in 670 and held them until 692, when the Chinese finally managed to regain these territories. ==Death and succession==