Map Introduction

The historical evolution of Yang Province under the rule of the Wu state during the Three Kingdoms period (220–280 AD) was primarily reflected in political transitions and military strategic arrangements:

Political Transitions
- Rule of the Wu State: During the tripartite division of China, Yang Province was part of Wu's territory. In the eighth year of the Chiwu era (245 AD), Wu established Danyang Commandery, which administered counties such as Guangling and Jiangdu, serving as a military and administrative center.
- Eastern Wu Regime: After Sun Quan founded the Eastern Wu regime, the name "Yang Province" was retained as an administrative division, though its actual controlled territory fluctuated with the tides of war. For instance, during Sun Xiu's reign (258–264 AD), the capital was briefly moved to Jianye (modern Nanjing), yet Yang Province maintained its critical role as a military stronghold.

Military Strategic Significance
- Jiang-Huai Defense Line: Yang Province occupied a strategic position at the confluence of the Yangtze and Huai rivers, making it a key defensive region for Wu against northern powers. In 486 BC, King Fuchai of Wu excavated the Hangou Canal (modern Yangzhou section), connecting the Yangtze and Huai rivers. This early canal system facilitated material transport and enhanced military logistics.
- Wei-Wu Contention: The Wei and Wu states repeatedly clashed in the Yang Province area. For example, Cao Pi led attacks on Wu-held territories such as Hefei and Guangling, while Wu stationed significant forces there for defense.

Administrative Adjustments
- Post-Eastern Jin Period: Yang Province briefly fell under Jin control but was quickly reclaimed by Eastern Wu. During the Northern and Southern Dynasties, Yang Province continued to function as a military hub, though its specific administrative structure evolved with successive dynastic changes.

During this period, Yang Province was not only a political and military center but also, through its canal network, sustained the logistical supply chain of the Jiang-Huai region, becoming an indispensable strategic pivot within the tripartite balance of power.