Penal servitude (tu 徒) was one of the five capital punishments (wuxing 五刑) in traditional China. It was the third-highest penalty, after exile (liu 流) and execution (si 死). Penal servitude was seen as a status of slavery and shame, and therefore had a deep impact on a convict's personal status. It is first seen in oracle bone inscriptions, with the designation yu 圉. In antiquity, servitude was combined with all punishments except the death penalty.
According to the ritual Classic Zhouli 周禮, tatooed persons (mo 墨), for instance, served as gatekeepers (shou men 守門), persons castrated persons (gong 宮) served in the royal palace (shou nei 守内, as eunuchs), convicts whose foot was cut off (yue 刖) protected the royal gardens (shou yu 守囿), and those convicted to have their heads shaved (wu 髡, nai 耐), had to protect the royal provisions (shou ji 守積).
The Qin 秦 (221-206 BCE) and Han 漢 (206 BCE-220 CE) dynasties knew quite a range of different forms of penal servitude, with several levels of time and additional constraints. Men were commonly forced to participate in the construction of city walls or the Great Wall (called chengdan 城旦), while women were sentenced to serve in the granaries pounding grain (chong 舂). The lowest conviction was just to serve in these two fields (chengdan jiu 城旦舂), and after a set period, the service was over (wan 完). In graver cases, the delinquents were punished by one of the corporal punishments, like tattooing on the cheeks (jing 黥), tattooing and being cut off the nose (jing yi 黥劓), being cut off the left foot (zhan 斬 or yue 刖), or cut off the left foot and tattooed, or being cut off the right foot.
The third level was the sentence of shaving the head and bearing an iron ring around the neck (wu qian 髡鉗). When the punishments of mutilation were abolished by Emperor Wen 漢文帝 (r. 180-157 BCE), tattooing became the common method of increasing the sentence of penal servitude. The length of this servitude was between 4 and 5 years. From the legal regulations on the Qin Bamboo slips discovered in Shuihudi 睡虎地, close to Yunmeng 雲夢, Hubei (Yunmeng Qinjian 雲夢秦簡), it can be seen that convicts also served for other public works, for instance, as workers in the production of weapons, or in the public weaveries.
Some convicts were ordered to collect firewood for altars and temples. The men thus serving were called guixin 鬼薪, the females, caring for the grain, were known as baican 白粲. Yet the Bamboo Slips demonstrate that guixin and baican also served for earthworks and in the imperial workshops.
Other convicts were made public slaves, males were called lichen 隸臣, females liqie 隸妾. Under certain conditions, they were allowed to redeem their punishment either by sending a substitute person or by paying back a reward received for military honours (gongjue 功爵). Normally, public slaves served for three years (men) and two years, respectively (women). Public slavery was also the fate of relatives of convicts, because of the prevalent group liability. Apart from that, deserted soldiers, war captives, and children of public slaves also belonged to the convicts of this category. They served in a wide range of duties, from ploughing the fields and herding to carrying out construction work of each kind, military service, and surveying other convicts and labourers. In some forms of servitude (geng liqie 更隸妾), convicts were just obliged to serve in a certain time frame and were free otherwise. Old persons and very young ones were spared the penal servitude.
In order to save labour force, one dozen of convicts was supervised by one peer (sikou 司寇), who also carried out duties belonging to the administration, like driving chariots or cooking food. This was only possible for convicts sentenced to service of at least three years. After one year of hard work, they were allowed to become supervisor. This status was not as high as that of foreman (fazuo 罰作, and fuzuo 復作 for women), a position attainable after one year of service, and often as an act of grace. Some convicts were ordered to spy out (hou 候) the enemy or make out movement of bandits.
The Wei 曹魏 (220-265) and Jin 晉 (265-420) dynasties abolished the service of "wall builders" and "wood collectors", but retained the terms and penalties of shaving the head, which in effect served to designate the penal servitude per se. The penal code of the Jin dynasty knew three types of servitude, namely wuxing 髡刑, wanxing 完刑, and zuoxing 作刑, with several subcategories each, with different lengths and difficulties of servitude. The term tu 徒 was introduced by the Northern Wei dynasty 北魏 (386-534). This kind of servitude was also called nianxing 年刑, because they served for several years.
Apart from forcing the convicts to wear their heads shaved (therefore called neizui 耐罪), they were flogged and beaten, and some had to carry a plate around their neck. The possibility to buy oneself free from servitude was widened. The formalization of penal servitude progressed under the Northern Zhou 北周 (557-581) and the Sui 隋 (581-618) dynasties. There were five grades of penal servitude, namely one year (and 60 lashes with the whip, bian 鞭, and ten blows with the light stick), two years (70 lashes and 20 blows with the stick), three years (80; 30), four years (90; 40), and five years (100; 50). All sentences could be redeemed by payment of money.
The Tang dynasty 唐 (618-907) shortened the periods of sentence, three years being the longest. The additional corporal punishment was abolished, but the use of a plate around the neck was obligatory. The Song dynasty 宋 (960-1279) reintroduced the blows, but reduced their number (20 for three years, 18 for two and a half year, 17 for two years, 15 for one and a half year, and 13 for one year). In addition to that, the authorities were pleased with the corporal punishment, and servitude was not any more required. This fits with the general trend in the Song period to replace corvée labour or military service by open labour relations.
The system of penal servitude under the Liao dynasty 遼 (907-1125) was quite extraordinary. The severity of the three graded differed extremely, from lifelong sentence, 500 blows and tattooing on the cheek to one and half a year and no blows or tattooing. The Yuan dynasty 元 (1279-1368) also reintroduced high numbers of blows, and to make matters worse, ordered to use fetters (liao 鐐) for the convicts.
The Ming dynasty 明 (1368-1644) inherited the harsh system, with 60 blows for one year, 70 for one and a half, 80 for two years, 90 for two and a half, and 100 blows for three years of servitude. The Qing dynasty 清 (1644-1911) decided to lower the numbers by fifty per cent, but replaced the light with a heavy stick (daban 大板). The Kangxi Emperor 康熙 (r. 1662-1722) converted the 100 light blows to 40 heavy blows. The possibility to redeem the punishment by a monetary payment was regulated more in detail. Convicts were usually send to postal stations (yi 驛) in their home province. Bannermen were not subjected to the rules of penal servitude. Instead, they were forced to carry the cangue (jiahao 枷号, see penal instruments) around their neck, for a time depending on the gravitiy of the offence (20 days of cangue for one year of servitude, and five days in addition for each half year of further servitude), and were thus publicly humilitated. In really serious matters, the rule of replacement by wearing the cangue did not apply, and Bannermen were also sentenced to penal servitude.