Wu Hu - Wu Hu After The Fall of Northern Xiongnu

Wu Hu After The Fall of Northern Xiongnu

In the first century the Eastern Han Dynasty brought the Northern Xiongnu into submission by military measures. Hordes of herdsmen and the Southern Xiongnu, originally subdued by the Northern Xiongnu, began trading without having heavy tribute imposed on them. Horses and animal products were traded mainly for agricultural tools, such as the harrow and the plough, and clothing of which silk was most popular. In return those herdsmen helped defend the Han dynasty against any remaining Xiongnu. The more they engaged in commerce with the Chinese, the more they preferred to stay near China's border, to facilitate trade, instead of residing on the steppes of Manchuria and Mongolia.

Some groups of non-Xiongnu herdsmen even settled permanently within the Chinese borders, first of which was the Wuhuan (烏桓), who migrated to the area of today's Province of Liaoning during the era of Jiangwu (25–56). Note that the Southern Xiongnu migrated before the Wuhuan but not for commercial reasons.

Liaison among the dynasty and groups of herdsmen relied on mutual economic and military benefits. As the Northern Xiongnu, the masters of the Mongolian steppes and mortal enemy of the Han Dynasty, were still potent enough during the reigns of Emperor Ming, Emperor Zhang and Emperor He (58–105) to keep the volatile alliance intact, the Eastern Han dynasty enjoyed the most prosperous years of its almost 200 years of existence. Even fragments of the Northern Xiongnu migrated well within the border to the Xihe plain, west of the Huang He and south of the Ordos Desert).

The picture drastically changed in the later years of reign of Emperor He, son of Emperor Zhang. Dou Xian (50s–92), brother-in-law of Emperor Zhang through his sister Empress Duo, utterly defeated the Northern Xiongnu in a series of campaigns during the Yongyuan era (89–105). The remnants just escaped annihilation, conceded defeat, began migrating out of the Mongolian steppes and disappeared as a distinct group of herdsmen once and for all. Others were assimilated into other tribes by intermarriage: the Yuwen tribe being a good example.

In their wake a power vacuum was left on the Mongolian steppes. The main contenders were the Southern Xiongnu, who inhabited a region to the south of the steppe and had now grown into a group of more than a hundred thousand herdsmen on the Xihe plain, the Xianbei, who lived in the east of the steppe residing on the plains of Manchuria, the Dingling, who originally dwelt on the banks of Lake Baikal and had already commenced trekking south into the steppes before Duo Xian destroyed the Northern Xiongnu, and the Wuhuan, who lived south of the Xianbei and were the weakest of the four.

Instead of constantly trading for provisions, tools and luxuries, these four powerful groups of herdsmen, though still allies of the Han Dynasty, often cooperated to plunder areas of the northern border. The dynasty could not muster an all-out campaign to wipe them out, but often attempted, through diplomatic and monetary measures to split one or more groups from the alliance of herdsmen.

On the other hand the dynasty was constantly declining as clans of consorts and eunuchs engaged in a continuous struggle for power. Wealthy merchants and aristocrats were acquiring lands from peasants who had been cultivating their own land for years. "Landless" peasants had to come under the protection of the rich and so pay rent to these new landowners rather than pay taxes to the government. Coupled with bureaucratic corruption, tax revenues dropped dramatically. Large landholding families also took advantages of the weakness of central government and established their own armies. Increasingly governors of regions (the highest level) administered their territories as independent rulers. The recruitment of troops and tax collection could be carried out at the discretion of the regional governors, contributing to the disunity that led to the inevitable crumbling of China into the Three Kingdoms.

The dynasty also had to deal with the Qiang and Di on the western border, who had constantly been involved in skirmishes against the dynasty since the middle of Western Han Dynasty (around mid-1st century BC). As the Eastern Han Dynasty declined, the Qiang, nominal ancestors of modern Tibetans, began planning major invasions. Through spies and collaborators, the Han court knew about the situation and had to deploy soldiers near the border to fend off Qiang skirmishes and small-scale invasions.

Although few major Qiang invasions were carried out, never successfully, such a military deployment constantly drained the treasury and was a cradle for ambitious militarists, the most famous of whom was Dong Zhuo (130s–192), the pretender to the Han court from 189-192. The more the Han court weakened through domestic problems, the more the herdsmen craved the dynasty's wealth. The Wuhuan were a frequent ally with the Han court against Xianbei and the Southern Xiongnu, although they also sometimes allied with the Xiongnu to fend off joint attacks by the Han and Xianbei.

The Han court also deployed mercenaries from the Xianbei and Wuhuan for campaigns against the Wu Hu and to quell peasant insurgents. These mercenaries were often sympathetic to the peasant uprising and hence not trusted by the Han military authorities. However they were the best available option for suppressing the insurgents and consequently these soldiers were poorly treated by being deployed far away from their homeland, or in the most dangerous positions on the battlefield or by starving them of provisions and weapons. Thus military who could earn the trust of the Xianbei or Wuhuan would collaborate with the tribes for the sake of their own careers.

For instance a unit of about 5,000 Wuhuan cavalry that usually resided in You Province (part of modern northeastern Hebei and western Liaoning Province) was deployed in Southern Jing Province (in Hunan Province) for three consecutive years. The rebellions (187-189) of Zhang Chun (died 189) and Zhang Ju (died 189) in You Province in alliance with this Wuhuan cavalry unit marked the first of many such collaborations. Yuan Shao (140s–202) and Gongsun Zan (140s–199), two warlords of the end of Han Dynasty, also exploited Wuhuan and Xianbei respectively in their own quests for predominance. Ironically Gongsun Zan was the commander tasked with suppressing the rebellion of Zhang Chun and Zhang Ju.