Map Introduction

Historical Evolution of the Duji Circuit and Henan Circuit

I. Establishment and Initial Functions of the Henan Circuit

The Henan Circuit was one of the ten circuits established in the first year of the Zhenguan era (627 AD) of the Tang Dynasty. Initially functioning as a surveillance district, its jurisdiction encompassed the entirety of present-day Shandong and Henan provinces, as well as northern Anhui and northern Jiangsu. Its administrative seat was located in Luoyang County, Luozhou (northeast of modern-day Luoyang, Henan). The circuit derived its name from its geographical position "south of the Yellow River." It stretched east to the coast, west to Hangu Pass, south to the Huai River, and north to the Yellow River, governing 30 prefectures and superior prefectures, including Guo Zhou, Shan Zhou, Bian Zhou, and Xu Zhou, covering an area far exceeding that of the modern Henan Province. After adjustments in the 21st year of the Kaiyuan era (733 AD), the Henan Circuit's jurisdiction was reduced to 1 superior prefecture and 28 prefectures (comprising 126 counties), with the administrative seat moved to Junyi County, Bian Zhou (modern-day Kaifeng, Henan). The area surrounding Luoyang was assigned to the newly established Duji Circuit.

II. Formation and Tiered Management of the Duji Circuit

The Duji Circuit was separated from the Henan Circuit in the 21st year of the Kaiyuan era (733 AD). Centered around Luoyang, it adopted a tiered management model of "Imperial Guard Zone - Perimeter Guard Zone." Its core was the Henan Superior Prefecture (former Luo Zhou), while the Perimeter Guard Zone included six prefectures such as Zheng Zhou, Shan Zhou, Huai Zhou, and Ru Zhou. Its boundaries extended east to Zhongmu in Zheng Zhou, west to the Funiu Mountains, north to the Yellow River, and south to Ye County. This circuit fostered a dense urban cluster along the Grand Canal, with both handicraft industries (such as Luoyang's silk weaving and Gongyi's Tang tri-color pottery) and agricultural economies (featuring a twice-in-three-years harvest system) being relatively developed. Its commercial network was centered around the Southern Market in Luoyang (hosting over 4,000 merchant establishments).

III. Functional Shifts after the An Lushan Rebellion

Following the An Lushan Rebellion (755-763 AD), the administrative nature of both circuits underwent fundamental changes:

• Henan Circuit: Transitioned from a surveillance district to a de facto administrative region, merging with the Jiedushi system to form the foundation of the regional warlord domains. Its population experienced three distinct phases: a sharp decline during the rebellion, a recovery during the Yuanhe era, and another decline in the late Tang. The eastern part developed textile and salt industries, while in the western Shan-Guo mountainous areas, communities known as "Shanpeng," who lived by hunting, emerged.
• Duji Circuit: The Jingji Jiedushi was established in 756 AD, and the circuit gradually evolved into a local administrative entity. Its surveillance functions weakened, shifting instead towards coordinating the transport of grain tributes via canal (e.g., from Henan Superior Prefecture and Zheng Zhou to Chang'an) and maintaining security along the Grand Canal. It was ultimately superseded by the Jiedushi system.

IV. Refinement and Adjustments of Administrative Divisions

• Henan Circuit: By the late Kaiyuan era, its territory was clearly defined as the entirety of Shandong and Henan, plus northern Jiangsu and northern Anhui, including eastern prefectures like Xu Zhou and Si Zhou, with Shan Zhou and Guo Zhou serving as western barriers.
• Duji Circuit: During the Tianbao era (742-756 AD), its divisions were further refined. The Henan Superior Prefecture administered 24 counties (including Gongyi and Dengfeng), while Ru Zhou administered 7 counties (including Ye County and Xiangcheng). This formed a "dual-core" structure centered on Luoyang (mirroring the Chang'an Jingji Circuit).

V. Economic Features and Historical Impact

• Economy: The Duji Circuit leveraged the water transport of the Bianhe Canal section, with Luoyang's Southern Market becoming a national commercial hub. The Henan Circuit developed a regional economic complementarity, with salt industries in the east and a hunting-based economy in the west.
• Military: In the 4th year of the Chuigong era (688 AD), the Heyang Area Commander was established in the Duji Circuit to strengthen the Yellow River defense line. During the An Lushan Rebellion, it became a key strategic area contested by Tang forces and the rebels.
• Institutional Influence: The evolution of these two circuits reflects the Tang Dynasty's transition from surveillance districts to regional warlord domains, providing a reference for later local administrative systems (such as the Song Dynasty's Lu system).

VI. Conclusion

The evolution of the Duji and Henan Circuits exemplifies the interplay between centralization and regional fragmentation in the Tang Dynasty. Their transformation from surveillance districts in the early Zhenguan era to administrative regions after the An Lushan Rebellion, along with shifts in their functions, territories, and economic structures, profoundly influenced the political landscape and regional development of the mid to late Tang period.