The lands of Central Asia have long appeared to be somewhat more attractive to would-be conquerors than they really are. The names of cities such as Tashkent and Samarkand are fabled as rich and exotic ports of call on the Silk Road. In reality, the region has historically been too remote for most of the great empires of east and west to be able to control it. Only those from the north, specifically the Mongols, were ever successful in incorporating the area into a wider state before the twentieth century.
In the eighth century CE, central Asia was faced with China to the east and the emergent Arab state to the west. Fuelled by promises of slaughter and pillage, Arab armies had rapidly seized control of much the region we now know as the Middle East and beyond. Yet Transoxiana – Central Asia – proved to be the limit for terrestrial and temporal control. While Islamicisation continued to the east, this was no longer accompanied by physical occupation and control by Arab armies. In China, meanwhile, the expansion of Chinese interests launched by the vigorous Tang dynasty was coming to a painful halt. Defeats in the north and south had seemed to demonstrate natural limits to the expansion of the Chinese empire. To the west, the rapid mobility of the Turkic and other horse based nomads was such that the system of expeditionary armies that the Tangs had used to conquer peoples living on the fringes of the empire were no longer effective. The distance from the imperial centre and the inability of armies to defeat swifter moving foes decisively meant that armies were away on campaign for increasing periods of time, rendering logistics an ever more difficult problem. A process began by which expeditionary armies became permanent settled garrisons on the borders of the empire. Faced with the prospect of being away from home for years, fewer and fewer volunteers were available to join these armies under the previously existing
fubing system by which each man was allotted a sufficient piece of land to feed himself and his family. Instead, armies had to be created from peasant conscripts, with often disastrous results.
Permanent settlement of fortress troops led to the increased power of local commanders, who had time and space to enforce their personal rule throughout the land under their purview. They might autonomously decide to take actions based on their local knowledge, rather than wait for a perhaps poorly-informed decision to reach them from the capital. Gao Xianzhi. Military governor of Anxi, decided in 751 to intervene on the side of his local neighbour Ferghana in its dispute with Tashkent. This brought him directly into conflict with Ziyad bin Salih, the governor of Samarkand under the Ummayyad Caliphate, who took the side of Tashkent. Gao’s 30,000 men met the Arab army at Talas in the Tarim Basin, north of the Tibetan plateau and a forbidding place to travel or seek to conduct warfare. Gao’s army, like most of the rest of those on Chinese frontiers, was composed of a variety of Chinese and local tribes forces. Finding sufficient horses to mount an effective cavalry wing had for long been a major problem for the Chinese military. One of the solutions was to enlist local tribes into the regular military to assist with this function. Alas for Gao, this was a period of history in which the non-Chinese troops were looked down upon and treated as subordinates who must be kept on a tight rein. Perhaps as a result of this, an eastern Turkish tribe defected to the Arab army during the battle and this was the decisive action. Gao’s army was routed and the field left in the hands of the Arabs.
