(Provinicial) surveillance commissioners (anchashi 按察使) were high officials especially commissioned with the supervision of judicial administration. The office was founded by the Tang dynasty 唐 (618-907) with the aim to control the performance of local officials. In 711 Emperor Ruizong 唐睿宗 (r. 684, 710-712) divided the empire into ten circuits (dao 道), to each of which a surveillance commissioner was dispatched. During the reign of Emperor Xuanzong 唐玄宗 (r. 712-755) the office was called ancha caifang chuzhi shi 按察採訪處置使 (see caifangshi 採訪使), and additional commissioners were appointed for the control of the capital (Jingdu 京都) Chang'an 長安 (today's Xi'an 西安, Shaanxi), and for the two metropolitan regions (liangji 兩畿, i.e. Chang'an and Luoyang - today in Henan). In 732 the title caifang chuzhi shi 採訪處置使 was chosen to designate the office, and from 758 on the name surveillance and supervisory commissioner (guancha chuzhi shi 觀察處置使) was used. Surveillance commissioners acted in a similar way as regional inspectors (cishi 刺史), and had the right to control the financial and judicial administration and the general effectiveness of local governments, and to notify corrupt or lazy officials.
The Song dynasty 宋 (960-1279) abolished the office of military commissioner (jiedushi 節度使), and judicial matters were first carried out by transport commissioners (zhuanyunshi 轉運使), later by specialized officials called judicial commissioners (tidian xingyu gongshi 提點刑獄公使).
The Jin dynasty 金 (1115-1234) changed this name in 1199 to anchashi. Surveillance commissioners had the official rank 3A and were responsible for the judicial administration of territorial units. They assessed the performance of officials and pointed at shortcomings in a wide range of matters, even in farming and sericulture.
The Yuan dynasty 元 (1279-1368) called the office first provincial surveillance commission (tixing anchashi 提刑按察司), but then renamed it surveillance commission (suzheng liangfangsi 肅政廉訪司). The commissioners had rank 3A and the right to control all local officials of rank 6 and lower. Unlike before, they had the exclusive right to investigate judicial matters, and not any more the duty of an overall censorship of administrative performance. Surveillance commissioners sent a report to the Ministry of Personnel (libu 吏部), which decided over further promotion.
The Ming dynasty 明 (1368-1644) followed this predecent and appointed a tixing ancha si 刑按察使司 (short anchasi 按察司) in each province, whose superior was an anchashi. Other common terms for the office were gaosi 皋司, gaotai 皋臺, nietai 臬臺, waitai 外臺 or lianfang 廉訪.
During the Qing period 清 (1644-1911) surveillance commissioners (also known with the term niesi 臬司) belonged to the top government of the provinces, in third place after the administration commissioners (buzhengshi 布政使) and the provincial governors (xunfu 巡撫). These three were known as the provincial authorities (du-fu dayuan 督撫大員). In important trials, the surveillance commissioners cooperated with the administration commissioners (the two commissioners, liangsi 兩司) in search for a solution. Surveillance commissioners were also responsible for the courier service in a province, and supervised in the function of an examination overseer (jianshiguan 監試官) the provincial examinations (xiangshi 鄉試, also called dabi 大比, see examination system) carried out once all three years. Also every three years, the great evaluation (daji 大計) of all provincial officials was carried out, during which the surveillance commissioners had the role of evaluation overseers (kaochaguan 考察官). During the annual autumn assizes (qiushen 秋審) they had the role of *chief drafters (zhugaoguan 主稿官).
In 1911 the office was renamed commissioner for judicial affairs (tifashi 提法使), but was soon abolished.