The Establishment of Longxi Commandery by the Qin: A Military and Economic Hub on the Western Frontier of the Empire

Brief Introduction

In the Hanshu (Book of Han), specifically within the Geographical Gazetteer (Geography and Localities chapter), the phrase "established by the Qin" (Qin zhi) is frequently used as a note indicating the founding date of a commandery or county. It signifies that the administrative region was established or formally organized during the Qin Dynasty. The establishment of Longxi Commandery was a critical step in the Qin's unified control over the west, opening up routes to the Western Regions and the area inhabited by the Tuyuhun. It was not only a marker of the extension of the Qin's commandery-county system to the northwestern frontier but also laid a solid administrative and military foundation for the Han Dynasty's operations in the Hexi Corridor and its defense against the Qiang people.

Core Knowledge Points

1. The Historical Connotation of "Established by the Qin"

In the Hanshu, "established by the Qin" does not merely mean "set up by the Qin Dynasty"; it implicitly reflects the logic behind the promotion of the commandery-county system in the Qin era. After Qin Shi Huang unified the Six Kingdoms, he abolished the feudal system and implemented the commandery-county system. The territory of Longxi Commandery roughly corresponds to today's Tianshui and Dingxi areas in Gansu Province. It represented the formal integration of newly conquered lands into the central direct administration following the Qin's conquest of the Yiqiu. This move broke the existing geopolitical landscape where tribal groups like the Rong and Di ruled themselves and established the direct jurisdiction of the Central Plains dynasties over the northwest.

2. The Geographical Strategic Value of Longxi Commandery

Located at the eastern end of the Hexi Corridor, with the Qiang lands to the south and Chang'an (Jingzhao) to the east, Longxi Commandery served as the first gateway for the Guanzhong Plain's radiation into the northwest. It guarded the transition zone between the Loess Plateau and the Tibetan Plateau. It functioned as a logistics transit hub for western military campaigns and a critical barrier for the Central Plains dynasties against northern Xiongnu and western Qiang incursions. The Qin's establishment of the commandery here was, in essence, a military deployment to "hold the high ground, control the waterways, occupy strategic passes, and regulate the barbarians."

3. Correspondence with the Geographical Gazetteer of the Hanshu

Under the entry for Longxi Commandery in the Hanshu: Geographical Gazetteer, detailed records are provided of its subordinate counties (such as Ddao and Lintao), as well as population and household figures, explicitly noting "established by the Qin." This method of annotation reflects Ban Gu's rigorous style of textual criticism, clearly outlining the timeline of local administrative setups. Later researchers can determine whether a commandery underwent changes during the Han Dynasty (such as territorial expansion or relocation of the administrative seat) by comparing terms like "established by the Qin" with "established by the Qin, continued by the Han."

Relevance to the Book's Content

In the Hanshu: Geographical Gazetteer, Longxi Commandery is listed under the jurisdiction of the Inspector-General of Yong Province. This record reflects the Han administrative system—although "established by the Qin," it remained part of the Central Authority's Thirteen Provincial Departments during the Han period, subject to oversight by the Cishi (Inspector). Furthermore, mentions in the Hanshu: Biography of the Xiongnu and Biography of the Western Regions of Han generals campaigning in the Western Regions and quelling Qiang rebellions often relied on Longxi Commandery as a logistical base. For example, during the reign of Emperor Wu of Han, before Li Guangli attacked Dayuan (Fergana), military supplies were transported via Longxi. Ban Chao's operations in the Western Regions also had a strategic depth that included the Longxi corridor, which had already been civilized during the Qin period.

Although the phrase "established by the Qin" is brief, it condenses the historical continuity from the foundation laid by the Qin to its continuation in the Han. It is not just a marker of administrative division but a key entry point for understanding the border governance, ethnic interactions, and military logistics systems of the Qin-Han Empire. Through this knowledge point, readers can glimpse the internal logic of how the ancient Chinese centralized system effectively extended its reach to the frontiers.