Strategic Background
The Battle of Chibi had just ended; Cao Cao's strength had not yet recovered. Jiangling and Xiangyang were held by Cao Ren and Xu Huang, while the Huainan front was comparatively thin. Sun Quan at this moment enjoyed an unprecedented strategic initiative: the Nanjun was still being contested by Zhou Yu against Cao Ren; Jiangxia was secure; a main force could be drawn from Jiangdong's own garrison and sent north into Huainan. Geographically, Hefei meant to Eastern Wu what Wancheng meant to Jingzhou — it commanded the land-and-water corridor connecting Lake Chaohu to the Fei River, the only hub through which Wu's warships could pass from the Yangtze into the Huai River. Sun Quan's decision to personally lead one hundred thousand troops to besiege Hefei was not simply "pursuing a retreating enemy"; it was an attempt to use the political window opened by the Chibi victory to push Jiangdong's reach from the Yangtze to the Huai, advancing the front line of future campaigns against Wei from the interior of the Jiangbei plain out to the interior of Huainan.
Dispositions of Both Sides
On the Wu side, Sun Quan personally led the main force north, aiming for a quick decision. The fleet took the Chaohu route into the Fei River and anchored below the walls of Hefei; the land army completed the encirclement. Eastern Wu's advantage was convenient water transport and ample supply; its weakness was the absence of heavy siege equipment and sustained assault experience needed to reduce a fortified city. On the Wei side, Hefei's defenses had been built up for many years by Liu Fu, the Inspector of Yangzhou. Liu Fu was the Inspector of Yangzhou appointed by Cao Cao in the early Jian'an years; he had entered Hefei alone on horseback, rallied displaced refugees, accumulated granary stores, repaired walls, and stockpiled siege-defense equipment including large quantities of straw mats and oil-soaked stones, turning Hefei into a fortress capable of sustained independent resistance. Even though Liu Fu himself had already died before Sun Quan arrived, the defensive system he had built was still able to withstand a prolonged siege on its own.
Key Decision Points
The pivotal points of this battle are three. The first is whether Sun Quan chose "swift assault" or "prolonged siege." The Wu army initially attempted a swift assault; after repeated days of unsuccessful frontal attack, it shifted to a sustained blockade — but then faced the risk of its supply line from the Huainan direction being cut by a Wei relief force. The second is whether Hefei received timely reinforcement from Cao Cao. After retreating from Chibi, Cao Cao did not immediately move to save Jiangling but prioritized sending relief to Huainan — a choice reflecting his assessment that Hefei's strategic value exceeded Jiangling's. Units under Zhang Xi and others moved south, placing Sun Quan in a dilemma. The third is Sun Quan's risk assessment of having "Jiangdong's main force suspended north of the Yangtze." Once Cao Cao arrived in Huainan personally, the Wu army risked having its Fei River supply line severed. Sun Quan resolved to lift the siege and withdraw, avoiding the catastrophe — the kind of being cut off and ambushed by Zhang Liao that would materialize in 215 at Xiaoyaojin.
Outcomes and Resonance
The siege ended with Sun Quan withdrawing without taking Hefei. But the reverberations of this battle far exceeded its tactical result. Strategically, Cao Cao now understood that Hefei was an indispensable fortress on the Wei-Wu boundary; subsequent generations under Cao Pi and Cao Rui reinforced it continuously, and with Zhang Liao, Le Jin, Li Dian, Man Chong, and others garrisoning it in succession it developed into the core hub of the anti-Wu defense system. On the Eastern Wu side, Sun Quan's fixation on Hefei calcified from this point forward — his second siege of Hefei in 214, his defeat at Xiaoyaojin in 215, and the Hefeixincheng campaign of 234 were all continuations of this same strategic thread. Over more than forty years Eastern Wu mounted more than ten assaults on Hefei; not once did it take the city. This became the starting-point of Eastern Wu's enduring strategic impasse of "never being able to break through in Huainan."
Counterfactual Analysis
Had Liu Fu not spent ten years conscientiously building Hefei's defenses in the early Jian'an years, Sun Quan's hundred thousand troops would very likely have breached the city within twenty to thirty days. Once Hefei fell into Wu's hands, Jiangdong's power would have commanded the water corridor of Chaohu–Fei River–Huai River, compressing Cao Cao's strategic depth in Huainan to the Shouchun line, and the entire San Guo configuration might have tilted immediately after Chibi toward "Wu strong, Wei weak." Conversely, had Sun Quan stubbornly persisted in a prolonged siege as Cao Cao's relief force closed in rather than withdrawing, the consequences of Wu's main force being cut off would have been catastrophic — the territory south of the Yangtze might have been flanked from the Jiangxia–Jiujiang direction while the main force was tied up abroad, causing severe damage to Jiangdong's foundations. Sun Quan's prompt withdrawal, though "without achievement" at the tactical level, preserved the fruits of the Chibi victory at the strategic level, leaving room for Zhou Yu to advance westward into Jiangling and partition Jingzhou jointly with Liu Bei.