 The Tang campaign against Kucha was a military campaign led by the Tang Dynasty general Ashina She 'er against the Tarim Basin oasis state of Kucha in Xinjiang , which was aligned with the Western Turkic Khaganate . The campaign began in 648 and ended on 19 January 649 , after the surrender of the Kuchan forces following a forty @-@ day siege in Aksu . Kuchean soldiers tried to recapture the kingdom with the assistance of the Western Turkic Khaganate , but were defeated by the Tang army . 
