The office of regional inspector (cishi 刺史) was created during the Former Han period 前漢 (206 BCE-8 CE) in order to control and supervise the officials in the thirteen provinces (zhou 州). The first regional inspectors were appointed in 106 BCE, yet inspecting offices had already been created by the Qin (see Censorate). They had no administrative seat, but toured the province under their jurisdiction, observed how the official duties were carried out in each commandery (jun 郡) and princedom (guo 國), and in particular checked judicial matters.
They made use of a catalogue of six criteria (liutiao 六條), namely 1) whether the powerful local families did not acquire so much land that the peasantry impoverished, 2) whether the governors (taishou 太守) of the commanderies were observing the bureaucratic rules and working for the public, and not for their profit, 3) whether they rendered fair and objective judgments unswayed by personal emotions, 4) whether they hired competent personnel, and not just favourites and relatives, 5) whether the subordinated personnel was working decently and obeyed the governor's orders, and 6) whether they were corrupt and oppressive. The metropolitan region was controlled by a metropolitan commandant (sili xiaowei 司隸校尉). The official rank corresponded to a salary of 600 bushels (shi 石, see weights and measures) of grain, which was actually less than that of the governors of commanderies.
Over time these conditions changed and some inspectors were given the title of regional governors (zhoumu 州牧, mu 牧). The inspection tour began in autumn, and at the end of the year each inspector submitted a report to the throne. From the later Former Han period on regional inspectors began to interfere into local matters like the appointment of subordinated officials (xuanju 選舉) or in judicial verdicts (hezou 劾奏).
In the Later Han period 後漢 (25-220 CE) the inspection was not any more carried out by the cishi themselves, but by subordinated officials, like retainer clerks (congshishi 從事史) or clerical aides (jiazuo 假佐). The inspectors themselves resided in a fix place, with the consequence that they were in fact provincial governors. With the numerous peasant rebellions occurring in the late second century CE, the cishi were also given military responsibilities, with powers which they continued to practice during the Three Kingdoms period 三國 (220-280). This tendency increased during the Jin period 晉 (265-420), and some 'inspector-governors' were granted the title of commander-in-chief (dudu 都督) or general (jiangjun 將軍). Those without the concurrent title of general were called "restricted regional inspectors" (danche cishi 單車刺史). The duty of the cishi of inspecting officialdom was given up, and they became administrators by themselves, in both civilian and military matters.
There were in total three classes of cishi (civilian and military matters, rank 2; military matters, rank 4; and just civilian matters, rank 5), from the Liang period 梁 (502-557) on six. The highest class had their own offices and staff. At that time the nominal salary of a cishi was 2,000 bushels of grain. The Northern Wei dynasty 北魏 (386-534) even increased the power of the inspector-governors. The highest of them, overseeing the capital, was called metropolitan commandant (sizhou mu 司州牧). In the later phase of the Northern Dynasties period 北朝 (386-581), there were three inspector-governors for each province.
Emperor Yang 隋煬帝 (r. 604-617) of the Sui Dynasty 隋 (581-618) abolished the commanderies. This had the consequence that the cishi were renamed governors, which was actually a lower position, and from then on directly administered the districts of the empire. In the metropolitan region, fourteen cishi were appointed who were responsible for touring the districts for inspection, as it had been common during the Han period. The Tang Dynasty 唐 (618-907) reintroduced an intermediate territorial unit (the former commanderies), calling it zhou (prefectures). Regional inspectors were therefore responsible for much smaller territories than before. The Tang further introduced the use of an official flag (chijie 持節) and a type of warrant (jiajie 假節) for the inspectors, but in practice, they only used a bronze fish (tongyu 銅魚) as a 'badge of office'.
Tang-period cishi commanded a large staff with administrators (zhangshi 長史), commanders (sima 司馬), administrative aides (biejia 別駕), administrative supervisors (lushi canjun 錄事參軍) and administrators of personnel (sigong canjunshi 司功參軍事), of granaries (sicang canjunshi 司倉參軍事), of revenue (sihu canjunshi 司戶參軍事), of state farms (sitian canjunshi 司田參軍事), of military (sibing canjunshi 司兵參軍事), of law (sifa canjunshi 司法參軍事) and of requisitioned labour (sishi canjunshi 司士參軍事). From the mid-Tang period on the cishi were concurrently defence commissioners (fangyu shi 防禦使) or military training commissioners (tuanlian shi 團練使). They were furthermore subordinated to the military commissioners (jiedushi 節度使) and surveillance commissioners (guanchashi 觀察使).
During the Song period 宋 (960-1279) cishi was just a brevet title and their bearers were so-called salary officials (jiluguan 寄祿官, rank 5) of military nature who received pay, but did not have concrete duties. The office of cishi was abolished by the Yuan, but the term was still used as an unofficial designation for prefects (zhizhou 知州) until the end of the Qing empire 清 (1644-1912).