Tibetans Capture Chang'an
The event known as the "Tibetans Capture Chang'an" occurred in 763 during a period of significant turmoil and power shifts in Central Asia. By this time, the region was dominated by four major powers: the Tibetans, the Turks, the Arabs, and the Chinese, each vying for control over vital trade routes and territories. Following a series of military conflicts, the Tang Dynasty of China, under Emperor Daizong, had initially managed to expand its influence but faced challenges after the onset of the An Lushan rebellion in 755, which diverted military resources and weakened Chinese control.
Seizing the opportunity created by this internal strife, the Tibetans launched attacks against Chinese forces, ultimately leading to their entry into Chang'an, the capital of the Tang Dynasty. Although the Tibetans did not remain in the city for long and left after plundering it, their capture symbolized a crucial shift in the balance of power in the region. This event marked a decline in Chinese influence and the beginning of a new geopolitical landscape, where nomadic tribes began to play a more significant role in Chinese internal affairs. The aftermath saw the Tibetans reinforcing their power and establishing alliances, while the Chinese were left to navigate a changing political reality that would influence their strategies for years to come.
Tibetans Capture Chang'an
Date 763
Locale Tibetan plateau (now the Tibet Autonomous Region, People’s Republic of China), western China, and Central Asia
For a brief period, the forces of the Tibetan Empire occupied the Tang Dynasty capital of Chang’an (Xi’an).
Key Figures
Me Agtsom (704-755), emperor of Tibet, r. ?-755Trisong Detsen (742-797), emperor of Tibet, r. 755-797Xuanzong (Hsüan-tsung; 685-762), Tang emperor, also known as the Brilliant Emperor, r. 712-756Suzong (Su-tsung; 711-762), Tang emperor, son of Xuanzong, r. 756-762Daizong (Tai-tsung; 727-779) Tang emperor, r. 762-779An Lushan (An Lu-shan, d. 757), Chinese general, leader of the great rebellion of 755
Summary of Event
By 730, an uneasy peace had settled on Central Asia. The four major powers of the region—the Arab states to the far west, the Tibetans to the south, the Turks to the northeast in what is now known as Mongolia, and the Chinese to the southeast—had fought themselves to a temporary standstill. Each power had similar goals: to maintain dominance over or parity with the others and to either control or maintain access to the major trade routes that crossed Central Asia from China to the west. To accomplish these goals, they had engaged in outright conquest of small, independent polities; established colonies along trade routes; created vassal states through alliance and treaty; and fomented rebellion whenever necessary. Both the Tibetans and the Turks had formal peace treaties with the Chinese but also maintained a military and political alliance with each other and sought as allies to control far western Central Asia.
The Chinese learned of this alliance from small vassal states that sought protection from the incursions of Tibetan and Turkic forces after 734. Xuanzong, the Tang Dynasty (T’ang; 618-907) emperor, ordered the administrators of his colonies to the north and west of the Pamir Mountains to begin negotiations for a military alliance with the Arab states of that region despite long-standing hostilities between them. The Chinese attacked both beginning in 737, defeating first the Turks and then the Tibetans. By 740, the Chinese had crippled Tibetan ambitions in the far west and had taken over large parts of northeastern Tibet, which, despite constant battles, remained in Chinese hands for the next decade.
Indeed, the Tang Dynasty had reached the peak of its political and military power by 750. The Tang had established colonies in the Tarim Basin, ruled a series of vassal states from the east into the Pamirs, and fully dominated the weakened Turks both militarily and politically. The Arabs in the far west had recovered from their earlier defeats and a series of local rebellions, such that they once again became a serious rival to Chinese hegemony of Central Asia. Tibet, meanwhile, had succumbed to the endemic problem of factional politics at the royal court, where the emperor, Me Agtsom, had attempted to promote Buddhism but was fiercely resisted by Bonpo priests and their allies. By 755, he had been assassinated during these struggles, and Tibetan fortunes had reached their lowest ebb. Tang China seemed invincible.
Chinese fortunes collapsed dramatically, however, in 755. An Lushan, a Chinese general and military administrator of the northeastern frontier, and of Sogdian and Turkic descent, led a massive rebellion against the Tang. An Lushan had been deeply involved in court politics, and Xuanzong’s favorite concubine, Yang Guifei (Yang Kuei-fei), adopted him as her son. A power struggle broke out between various factions, and An Lushan led his army against loyalist forces, inflicting defeat after defeat on them. The emperor and his court fled Chang’an (now Xi’an) in 756 en route to Sichuan. He sent his son, Suzong, northward with a small force; Suzong, on arrival at his destination, declared himself emperor. Xuanzong abdicated on hearing the news. Suzong wasted little time in consolidating his forces and recaptured Chang’an in 757, the same year in which An Lushan was killed by his own son. Although this was a major blow to the rebellion, it by no means ended it, and conflict between rebels and loyalists raged for another five years.
To counter the An Lushan rebellion, loyalist troops had been pulled from their posts in northeastern Tibet as well as the most important garrisons in Central Asia, and it did not take long for the Tibetans and others to take advantage of this newly created power vacuum. Former vassal states now paid homage and tribute to the Tibetan court, and the Tibetans began almost immediately to attack the remaining Chinese forces. After retaking their northeastern territories long held by the Chinese, they moved further to the east to the Chinese border towns in Sichuan and other areas in China proper along the margins of the plateau. By 763, they had moved far to the east and entered Chang’an late in the year. The newly installed Tang emperor, Daizong, son of Suzong, fled just in time to avoid capture. The Tibetans plundered the capital, and continued raiding further to the east.
Although they abandoned Chang’an after a few weeks, their military power continued unchecked, and by c. 780, they had overrun what is now the Chinese province of Gansu, which lies along the main path of the Silk Route. The Tibetans also re-established themselves as a force farther to the west, and through a series of alliances with Arabs, Qarluqs, and others, they made trade and travel on the major trade routes in Central Asia far safer. They, of course, benefited from this through heavy taxation of caravans.
Daizong, despite these setbacks, did not remain idle. He concluded a peace treaty in 783 with Trisong Detsen, the Tibetan emperor, and actually proposed a bilateral military agreement with the Tibetans, which they accepted based on a number of lavish promises made to them. However, well before that, he actively courted the Uighurs, a large nomadic polity in northern Central Asia, with hopes of making them an ally in his struggles with both the Tibetans and the rebels. In contrast to earlier emperors, who simply manipulated nomadic tribes for military or political advantage on the frontiers of empire, Daizong followed a course of appeasement and accommodation with the Uighurs so that they would help him maintain his position within China. They thus became intricately involved with the internal politics of the Chinese state. Although they did agree to align themselves with the Chinese, they proved to be fickle and rebelled, causing Daizong to invoke the treaty with the Tibetans, which they honored. However, the emperor failed to follow through with his promises, and this led to new hostilities with the Tibetans, who forced the Chinese to accept a peace treaty in 783. Although Daizong was able to hold onto his throne despite his conflicts with the Tibetans and rebellions of the Uighurs, the political and military power of the Tang Dynasty was broken, and it never recovered from the loss of its Central Asian colonies and access to the west.
Significance
The capture of Chang’an by the Tibetans in 763 was of little practical significance in the power struggles of the mid-eighth century in Central Asia. The Tibetans did not linger, and Daizong was able to restore his court fairly rapidly. However, the capture of Chang’an had a deeper geopolitical significance in that it represented the total collapse of Chinese political, military, and economic power in Central Asia. In the years after 755, China had no direct, unimpeded route to the west, and what trade did flow into it from that direction was carefully regulated by the Arabs, Tibetans, and others. China in fact lost a significant source of wealth with the closure of the trade routes. However, perhaps of even greater significance is the change in the relationship the Chinese had enjoyed with the nomadic tribes to the north. For most of its history, the Chinese used these tribes as political pawns and manipulated them from afar for their geopolitical ends. However, the An Lushan rebellion changed this relationship and created a pattern whereby nomadic tribes, first the Uighurs, then a series of others until the Mongols, became intimately involved in the internal politics of the Chinese state. The Chinese emperors thus increasingly relied on foreigners to maintain internal political stability.
Bibliography
Beckwith, Christopher S. The Tibetan Empire in Central Asia. Princeton, N.J.: Princeton University Press, 1987. The definitive treatment of the expansion of the Tibetan Empire into Central Asia.
Pulleyblank, Edwin G. The Background of the Rebellion of An Lu-shan. London: Oxford University Press, 1955. The definitive analysis of the rebellion that changed the face of Central Asia and China after 755.
Stein, R. A. Tibetan Civilization. Stanford, Calif.: Stanford University Press, 1972. Useful and accessible historical overview of Tibet’s history and culture.