Under Xianzong (reigned 805–820) the Tang regained a great deal of its power. Xianzong, a tough and ruthless ruler who kept a firm hand on affairs, is notable chiefly for his successful policies toward the provinces. Rebellions in Sichuan (806) and the Yangtze delta (807) were quickly put down. After an abortive campaign (809–810) that was badly bungled by a favorite eunuch commander, the court was again forced to compromise with the governors of Hebei. A fresh wave of trouble came in 814–817 with a rebellion in Huaixi, in the upper Huai valley, that threatened the canal route. That uprising was crushed and the province divided up among its neighbors. The Pinglu army in Shandong rebelled in 818 and suffered the same fate. Xianzong thus restored the authority of the central government throughout most of the empire. His success was based largely upon the palace armies. The fact that these were controlled by eunuchs placed a great measure of power in the emperor’s hands. Under his weak successors, however, the eunuchs’ influence in politics proved a disaster.

Xianzong’s restoration of central authority involved more than military dominance. It was backed by a series of institutional measures designed to strengthen the power of the prefects and county magistrates, as against their provincial governors, by restoring to them the right of direct access to central government and giving them some measure of control over the military forces quartered within their jurisdiction. In an important financial reform, the provincial government no longer had first call on all the revenue of the province, as some revenue went directly to the capital. The government also began the policy, continued throughout the 9th and 10th centuries, of cutting down and fragmenting the provinces. It strengthened its control over the provincial administrations through a system of eunuch army supervisors, who were attached to the staff of each provincial governor. These eunuchs played an increasingly important role, not merely as sources of information and intelligence but as active agents of the emperor, able to intervene directly in local affairs.

The balance of power within the central government had also changed considerably. The emperor Dezong had begun to delegate a great deal of business, in particular the drafting of edicts and legislation, to his personal secretariat, the Hanlin Academy. Although the members of the Hanlin Academy were handpicked members of the bureaucracy, their positions as academicians were outside the regular official establishment. This eventually placed the power of decision and the detailed formulation of policy in the hands of a group that depended entirely on the emperor, thus threatening the authority of the regularly constituted ministers of the court.

The influence of the eunuchs had also begun to be formalized and institutionalized in the palace council; this provided the emperor with another personal secretariat, which controlled the conduct of official business and had close links with the eunuchs’ command of the powerful palace armies. The eunuchs’ influence in politics steadily increased. Xianzong was murdered by some of his eunuch attendants, and henceforth the chief eunuchs of the palace council and the palace armies were a factor in nearly every succession to the Tang throne; in some cases they had their own candidates enthroned in defiance of the previous emperor’s will. The emperor Wenzong (reigned 827–840) sought to destroy the dominance of the eunuchs; his abortive schemes only demoralized the bureaucracy, particularly after the Sweet Dew (Ganlu) coup of 835, which misfired and led to the deaths of several ministers and a number of other officials. But the apogee of the eunuchs’ power was brief, ending with the accession of Wuzong in 840. Wuzong and his minister, Li Deyu, managed to impose some restrictions on the eunuchs’ power, especially in the military.

In the second half of the 9th century the central government became progressively weaker. During Yizong’s reign (859–873) there was a resurgence of the eunuchs’ power and a constant fratricidal strife between eunuchs and officials at court. From the 830s onward the first signs of unrest and banditry had appeared in the Huai valley and Henan, and trouble spread to the Yangtze valley and the south beginning in 856. Major uprisings were led by Kang Quantai in southern Anhui in 858 and Qiu Fu in Zhejiang in 859. The situation was complicated by a costly war against the Nanzhao kingdom on the borders of the Chinese protectorate in Annam, which later spread to Sichuan and dragged on from 858 until 866. After the invaders had been suppressed, part of the garrison force that had been sent to Lingnan mutinied and, under its leader, Pang Xun, fought and plundered its way back to Henan, where it caused widespread havoc in 868 and 869, cutting the canal linking the capital to the loyal Yangtze and Huai provinces. In 870 war broke out again with Nanzhao.

Yizong was succeeded by Xizong (reigned 873–888), a boy of 11 who was the choice of the palace eunuchs. Prior to his ascension, Henan had repeatedly suffered serious floods. In addition, a wave of uprisings by farmers began in 874, following a terrible drought. The most formidable of them was led by Huang Chao, who in 878 marched south and sacked Guangzhou (Canton) and then marched to the north, where he took Luoyang in late 880 and Chang’an in 881. Although Huang Chao attempted to set up a regime in the capital, he proved cruel and inept. Hemmed in by loyal armies and provincial generals, in 883 he was forced to abandon Chang’an and withdraw to Henan and then to Shandong, where he died in 884. His forces were eventually defeated with the aid of Shatuo Turks, and the Tang court was left virtually powerless, its emperor a puppet manipulated by rival military leaders. The dynasty lingered on until 907, but the last quarter century was dominated by the generals and provincial warlords. With the progressive decline of the central government in the 880s and 890s, China fell apart into a number of virtually independent kingdoms. Unity was not restored until long after the Song dynasty was established.

The influence of Buddhism

The Tang emperors officially supported Daoism because of their claim to be descended from Laozi, but Buddhism continued to enjoy great favor and lavish imperial patronage through most of the period. The famous pilgrim Xuanzang, who went to India in 629 and returned in 645, was the most learned of Chinese monks and introduced new standards of exactness in his many translations from Sanskrit. The most significant development in this time was the growth of new Indigenous schools that adapted Buddhism to Chinese ways of thinking. Most prominent were the syncretistic Tiantai school, which sought to embrace all other schools in a single hierarchical system (even reaching out to include Confucianism), and the radically anti-textual, anti-metaphysical southern Chan (Zen) school, which had strong roots in Daoism. The popular preaching of the salvationist Pure Land sect was also important. After the rebellion of An Lushan, a nationalistic movement favoring Confucianism appeared, merging with the efforts of Tiantai Buddhism to graft Buddhist metaphysics onto Classical doctrine and lay the groundwork for the neo-Confucianism of the Song era.

In 843–845 the emperor Wuzong, a fanatical Daoist, proceeded to suppress Buddhism. One of his motives was economic. China was in a serious financial crisis, which Wuzong and his advisers hoped to solve by seizing the lands and wealth of the monasteries. The suppression was far-reaching: 40,000 shrines and temples—all but a select few—were closed, 260,000 monks and nuns were returned to lay life, and vast acreages of monastic lands were confiscated and sold and their enslaved people manumitted. The suppression was short-lived, but irreparable damage was done to Buddhist institutions. Buddhism had already begun to lose intellectual momentum, and this attack on it as a social institution marked the beginning of its decline in China.

Several types of monastic communities existed at the time. Official temples set up by the state had large endowments of land and property and large communities of monks who chose their own abbot and other officers. There were vast numbers of small village temples, shrines, and hermitages; these were often privately established, had little property, and were quite vulnerable to state policies. In addition, private temples or “merit cloisters” were established by great families, often to allow the family to donate its property and have it declared tax-exempt.

A monastic community was free of all obligations to the state. It could hold property without the process of division by inheritance that made the long-term preservation of individual and family fortunes almost impossible in Tang times. It acquired its wealth from those taking monastic vows, from gifts of pious laypersons, and from grants of lands by the state. The lands were worked by monastic enslaved people, dependent families, lay clerics who had taken partial vows but lived with their families, and tenants. Monasteries also operated oil presses and mills, and they were important credit institutions, supplying loans at interest and acting as pawnshops. They provided lodgings for travelers, operated hospitals and infirmaries, and cared for the aged. One of their most important social functions was offering primary education. The temples maintained their own schools, training the comparatively large proportion of the male population, which, although not educated to the standards of the Confucian elite or the clergy, was nevertheless literate.