Tang campaign against Kucha The Tang campaign against Kucha , known as Qiuci in Chinese sources , was a military campaign led by the Tang Dynasty general Ashina She ' er against the Tarim Basin oasis state of Kucha in Xinjiang . The campaign began in 648 and ended in 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 . The Tang court established a military garrison in Kucha , and placed the oasis state under the governance of the Anxi Protectorate . Hostilities between the Western Turkic Khaganate and the Tang Dynasty continued after the fall of Kucha . The Tang would later annex the khaganate after a military expedition in 657 . Background . Kucha , a kingdom in the Tarim Basin , was a vassal of the Western Turkic Khaganate . The oasis state was ruled by the Sufa royal family . Under the reign of Emperor Gaozu , the king Sufa Bushi provided the Tang court with tribute in 618 . In 630 , Bushi ' s successor Sufa Tie submitted to the Tang as a vassal . A Buddhist of the Hinayana sect , Tie had hosted the Buddhist monk Xuanzang when he arrived in Kucha during the same year . Kucha supported Karasahr when the oasis state ended its tributary relationship with the Tang court in 644 . The king of Kucha , Sufa Tie , renounced Tang suzerainty and allied with the Western Turks . Emperor Taizong responded by dispatching a military campaign led by the general Guo Xiaoke against Karasahr . Karasahr was besieged in 644 by Guo . Tang forces defeated the kingdom , captured the king , and a Tang loyalist was enthroned as ruler . The new king was deposed by his cousin , and the Tang once again intervened by sending a military expedition led by Ashina She ' er in 648 . After Karasahr fell , Ashina ' s army began its march towards Kucha . Ashina She ' er was a member of the Khaganate ' s ruling Ashina royal family . He joined the Tang forces after his surrender in 635 , and served as a general leading a campaign against Karakhoja . His familiarity with the region as a former Turkic ruler contributed to his success commanding the campaigns against Kucha and Karasahr . Prior to his recruitment as a Tang general , he reigned for five years between 630 and 635 , governing the cities of Beshbaliq and Karakhoja . Campaign . Ashina She ' er led his army to Kucha after the fall of Karasahr . Tie had died in 646 , and his brother Heli Bushibi inherited the throne as Kucha ' s king . Informed of the upcoming invasion , Bushibi tried to appease the Tang court by promising the kingdom ' s submission in 647 . The belated request did not work , and the attack commenced as planned . Ashina ' s soldiers were organized in five columns . The general eliminated sources of future reinforcements for Kucha by attacking Turkic tribes that had allied with the oasis state . He defeated Chuyue near Guzheng and the Chumi tribes inhabiting the Manas River . The forces defending Kucha , consisting of 50 , 000 soldiers , were lured and ambushed by Ashina . They chased after a group of 1 , 000 horsemen employed by Ashina as a decoy , but encountered additional Tang forces that mounted a surprise attack . The Kuchean forces were defeated and retreated to Aksu , a nearby kingdom in the Tarim Basin . Ashina captured the king following a forty - day siege , ending with the surrender of the Kucha forces on 19 January 649 . One of Ashina ' s officers , acting as a diplomat , persuaded the chieftains of the region to surrender instead of fighting back . Guo Xiaoke , who had led the first Tang campaign against Karasahr in 644 , was installed in the kingdom as protectorate - general of the Anxi Protectorate , or Protectorate to Pacify the West . While Ashina was in pursuit of the Kuchean king , Nali , a Kuchean lord , traveled to request the help of the Western Turks . Guo was assassinated after the Kuchean soldiers retook the kingdom with the military assistance of the Western Turks . Ashina returned to Kucha , captured five of the kingdom ' s cities , and forced the remaining cities to surrender . Tang control was re - established in the oasis state . The brother of the former king , a yabgu or viceroy , was enthroned by the Chinese as a subject of the Tang empire . The king of Kucha was taken to the Tang capital as a prisoner . Execution was the punishment of rebellion in accordance with Tang law . The king was pardoned by Taizong and released after a ritual venerating the emperor ' s ancestors . He was also named Great Army Commander for the Militant Guards of the Left , a title he received from the emperor . Aftermath . In retribution for the death of Guo Xiaoke , Ashina She ' er ordered the execution of eleven thousand Kuchean inhabitants by decapitation . It was recorded that " he destroyed five great towns and with them many myriads of men and women . . . the lands of the west were seized with terror . " After Kucha ' s defeat , Ashina dispatched a small force of light cavalry led by the lieutenant Sie Wanpei to Khotan , ruled by the king Fu Shouxin . The threat of an invasion persuaded the king to visit the Tang court in person . The conquest of Kucha established Tang rule over the northern Tarim Basin in Xinjiang . The region was governed under the same structure as the main prefectures of Tang China . Tang armies had annexed Karasahr and Karakhoja previously , while Kashgar , Khotan , and Yarkand had surrendered to the Tang voluntarily . Kucha became the center of the Anxi Protectorate in 649 , created in 640 to administer the parts of Xinjiang controlled by the Tang Dynasty . A Tang military garrison was installed in the oasis state as one of the Four Garrisons of Anxi , along with the garrisons in Kashgar , Khotan , and Karasahr . The fall of Kucha led to the decline of an Indo - European Tarim Basin . While Chinese rule had an impact on the culture of the region in the form of art and politics , the most significant change was the rising influence of Turkic language and culture . The composition of Tang armies in Central Asia contributed to this change . The majority of the Tang soldiers and generals stationed in the Tarim Basin by the Chinese were of Turkic ancestry . The Tang Dynasty continued their war against the Western Turks under the reign of Emperor Gaozong , Taizong ' s successor . Gaozong conducted a campaign led by general Su Dingfang against the Western Turk qaghan , Ashina Helu in 657 . The qaghan surrendered , the Western Turks were defeated , and the khaganate ' s former territories were annexed by the Tang . The Tang retreated from beyond the Pamir Mountains in modern Tajikistan and Afghanistan after a Turkic revolt in 662 , but retained a military presence in Xinjiang . The Tang , Tibetans , and Turks competed for influence in the Tarim Basin for the remainder of the dynasty . The Tang Dynasty ended in 907 with the abdication of Emperor Ai .