Warfare and Military Service

Warfare in early imperial China underwent certain profound changes over the course of the period of unified empires followed by the period without empires, changes which reflected the practices of preceding eras while also developing in their own right.

Having been used to forging war in such a manner, the Qin emperor did not hesitate to continue the practice. Besides, unification provided a larger pool of conscripts at the disposal of the new empire. The Qin state had mobilised hundreds of thousands of men for its conquest campaigns, and purportedly 600,000 people were used to conquer the southern kingdom of Chu. Offering his people no respite after the unification, the emperor launched a northern expedition - to repel the Xiongnu and build defensive works along the frontiers - and a southern expedition - to conquer the remote south and construct a canal for transportation and communication purposes.

The early Former Han rulers followed the practice of mass deployment of manpower in military operations; campaigns mobilising hundreds of thou­sands of men were therefore commonly seen. In addition, warfare in the early decades of the dynasty was mainly between the central government and the kingdoms enfeoffed to imperial princes, who divided up the eastern half of the empire with each having his own army. Such domestic warfare was in fact a continuation of the east versus west military confrontation between the Qin and its rivals, and was conducted within the Chinese realm, in which the topography suited infantry warfare. Infantrymen had assumed a dominant role since the Warring States period, not only because of the topography but

Violence and Warfare in Early Imperial China also because it was the type of military force that required the least time for training - compared with charioteers, cavalrymen and the navy - and thus would produce as many soldiers as possible within a fixed time frame. Universal military service provided the empire with a sufficient supply of conscripts who could be easily trained as infantrymen, which was compatible with the fashion for full-scale campaigns.

Such full-scale warfare was associated with heavy casualties. In addition to those who died in battle, the killing of captives also contributed to high death tolls. Having to frequently fight enemies with full-scale mobilisation in various directions meant exterminating one's rival forces as directly and quickly as possible was the preferred option. This explains the recurrent phenomenon of the massacre of war captives in the Warring States and early imperial ages.

After nearly a century of consolidation and development, during Emperor Wu's reign (r. 140-87 bce) the Han Empire's military landscape changed significantly and the practice of warfare had to alter and adapt to the new strategic conditions. The problem of rebellious kingdoms had been solved, and the most pressing military threat to the empire now was the Xiongnu steppe confederation.^[553] The Xiongnu usually preferred to launch sporadic cavalry raids rather than engage in pitched battles with the Chinese empire. The Chinese fashion of conducting full-scale mobilisation and campaigns for domestic warfare thus no longer met the needs arising from these new circumstances. What the Han Empire needed was a force that was capable of rapidly responding to the Xiongnu's raids, which meant professional

cavalry. Cavalry was not a new type of force for the Han Empire, but to have professional cavalry units required a lot of training in archery and horseman­ship and supplementary support - such as the breeding and training of horses. Furthermore, in order to safeguard its expanding territories, the Han Empire now needed to deploy garrison troops along the frontiers and even launch occasional expeditions beyond its borders.

The time of Emperor Wu was thus a transitional period in terms of the practice of warfare and the constitution of the Han military. On the one hand, the Han army still mobilised and launched operations in a full­scale manner and tried to achieve a total and decisive victory against the Xiongnu and other foreign foes; on the other hand, as such a manner was not compatible with foreign warfare, the Han army adapted to the change, and volunteers, convicts and mercenaries gradually replaced conscripts as the mainstay of the army, while cavalry units played an increasingly important role in military expeditions.^[554] Emperor Wu relied on the new army and launched a series of costly expeditions. Although his campaigns against the Xiongnu were not so successful as to bring them to heel, his military efforts did undermine the military might of the Xiongnu and destabilise the fragile balance of power within the steppe confederation, triggering internal conflicts.^[555] It was during the early Later Han that the Chinese empire finally drove the hostile Xiongnu away, while those Xiongnu who claimed loyalty to the Han emperor were permitted to settle along the northern frontiers of the empire. It was also in the early Later Han that the military transformation was formally completed with the official abolition of universal military conscription, ending a system that had underpinned military practices for centuries.^[556]

The Later Han maintained a standing army.

With the paralysis of Later Han administrations in the late second century ce, the state monopoly of violence broke down. Although waging war remained the largest task undertaken by the state in the following four centuries, the use of force moved out of unified state control and became devolved to regional warlords and local military strongmen. Incessant warfare and the weakening of officially sanctioned military power made violence widespread and a regular occurrence at various levels of society. To protect themselves, people led by local elites and magnates were usually organised into armed communities; some even formed mutual defence leagues. Fortified settlements placed in highly defensible positions became common, particularly in northern China, where the grave turmoil following the collapse of the Western Jin and violent conflicts between the so-called barbarian kingdoms pro­vided a hotbed for their flourishing. Local elites in the south also had armed forces at their disposal to enforce their will when needed, though their settlements were generally not as highly fortified as those of their northern counterparts. Refugees dislocated by war also swore allegiance to their leaders and transformed into armed bands, roaming around to seek safe havens. The widespread availability of various local military forces made it almost impossible for the state(s) to get rid of those forces militarily, and pacification was an alternative when necessary. Certain ambitious local elites chose to collaborate with alien rulers, vowing allegiance in exchange for personal political career advancement and, most importantly, state recognition of their de facto control of local affairs and command of private forces.^[558] In granting official recognition to the local leadership of private armies, state(s) also expected to divert these forces from private violence to sanctioned military services.

The prevalence of private military forces not only encouraged centrifugal energy against the state but also further aggravated the state's difficulty in maintaining a stable supply of troops. Shortage of manpower was a common problem facing different regimes, both south and north, between the third and sixth centuries. Since its abolition of universal military service, the Later Han had to rely upon professional standing troops rather than armies of conscripts that were temporary and disbanded after a campaign. The state might want to gather a large army, but the constraints imposed by a diminished martial population would not allow it. Conscription was no longer easy to carry out due to a drastic decrease in the registered population resulting from widespread dislocations and people's failing to register for fear of being drafted for war. To seek protection, some people turned to local magnates and served as private retainers.

The state had to compete with local powers for a supply of troops on the one hand, while also having to establish firm control over its existing forces on the other. As a result, hereditary soldiery was widely introduced. Once a man enrolled in the military, he would serve for a lifetime and be succeeded by another male family member after his death or in the case that he was unable to fulfil his duties. The soldier's family would be listed on the military instead of the civilian register. Military status was thus placed on a hereditary basis to ensure a constant supply of soldiers.

Various limitations were also imposed upon hereditary military households so as to separate them from commoners. Soldiery was not only an occupation but also a social caste with inferior legal status. Given their plight and unfavourable treatment, hereditary armies were seldom of high morale, and the state therefore needed to provide them with various incentives for fighting, including awarding the status of commoner after victory. But these measures did little to improve the difficult situations of most hereditary soldiers and mutinies were not rare; several cases even triggered large-scale uprisings which toppled the existing regimes.^[559]

Another common and effective way of acquiring manpower was to incorporate defeated enemies into one's military institutions. Hence, the massacre of war captives was rare compared with the Warring States and early Han periods. The belligerent parties widely recruited the defeated into their armies. Forcible migration was also taken as a supplementary measure to ensure a stable source of manpower. Once the state captured defeated armies or surrendered civilians, it would forcibly move and resettle them in the political centres or other strategic areas so that they would be at the state's disposal. This policy was particularly common in the north, given the nature of the barbarian regimes.

The barbarian ruling elites, whatever their ethnic origins, formed a powerful but small military minority within a much larger Han population. At first the distinction between the two groups was sharp, and the barbarian states relied primarily on their own compatriots to fight for regional hegemony.^[560] But as the wars went on, so rulers were under constant pressure to refill and enlarge their own forces, and thus had to recruit beyond their own ethnic group. In the Battle of the Fei River, for instance, the barbarian dynast who tried to conquer the south had incorporated myriad ethnic groups into his expeditionary force. Considering the comparatively limited number of warriors in every barbarian regime, other ethnic groups were welcome to join, and gradually even the Han majority was included - at first for ancillary duties and later in combat.

Since the martial population usually settled in fortified settlements or in political capitals, warfare in this period of disunity commonly centred on periodic sieges of massively defended fortifications and heavily fortified urban centres rather than on campaigns of manoeuvre. Historical records provide certain detailed accounts of siege warfare. For the southern dynas­ties, they were good at not only siege warfare - as a tradition of sedentary people - but also naval warfare. Given the networks of waterways in the south, naval warfare was frequent among the southern contenders. It also provided the south with a crucial strategic advantage over the northern invaders. Northern horseback warriors, especially the armoured heavy cavalry - the cataphracts - that were introduced and prevailed in this period, dominated the northern battlefield, but the southern waterways always imposed an insurmountable natural barrier.