Background
In 264, Eastern Wu faced the most severe external environment since its founding: Shuhan had been destroyed the previous year, the Simashi had taken full control of Caowei and were already showing signs of a dynasty change, and Jiangdong stood alone against a powerful enemy that had unified the central plains. At precisely this moment, Sun Xiu died of illness, leaving behind a young crown prince. Designating a young ruler would push Jiangdong into another round of powerful-minister monopoly, which was the last thing that the court officials — who had already lived through the lessons of Sun Lin's usurpation and Sun Xiu's restoration — wanted to see. Designating an adult member of the royal clan became the political consensus, and the twenty-three-year-old Marquis of Wucheng, Sun Hao, filled this vacancy.
Key Figures
Wan Yu was the matchmaker for this enthronement: he had spent many years in Wucheng with Sun Hao and knew his character well, yet chose to recommend him to Chancellor Puyang Xing and General Zhang Bu with the flattering assessment of "clear judgment and a love of learning." Puyang Xing had already survived the Ergongzhizheng and was a political veteran; Zhang Bu had been a core attendant minister of the Sun Xiu era; both controlled central and external military power, and their agreement effectively decided the outcome of the succession. The man enthroned, Sun Hao, was the son of the deposed crown prince Sun He; he had watched from childhood as his father was deposed, his mother cast aside, and himself excluded from the mainstream of the imperial clan — this childhood experience shaped in him an extreme distrust of power and a tendency toward revenge.
Core Issues
From a political-science standpoint, Sunhaojiwei involved three issues. The first is legitimacy under the agnatic order: as the son of Sun He, Sun Hao's bloodline was closer to the original firstborn legitimate son Sun Deng's branch than Sun Xiu's line, which is why he was accepted by veteran court officials who had opposed the Ergongzhizheng outcome. The second is the relationship with the Jiangdong great clans: Puyang Xing, Zhang Bu, and Wan Yu all belonged to the gentry clan network; they assumed that an adult emperor would make "ruler and minister governing together" easier, but underestimated Sun Hao's fear of and hostility toward powerful ministers. The third is the choice of external strategy — to hold the Yangtze in defense and govern well while waiting for the right moment, or to take the offensive and attempt to recover the central plains. Sun Hao's answer turned out to be the worst possible combination: internally brutal, diplomatically bellicose in appearance while militarily passive in practice.
Political Consequences
The brief honeymoon period after Sun Hao's enthronement lasted less than two years. Once power was consolidated, he immediately settled accounts with those who had installed him: Puyang Xing and Zhang Bu were put to the clan-execution penalty on the charge of "slandering court policies," eunuch Cen Hun was elevated to effective power, and the capital was relocated to Wuchang with massive construction projects, and then back to Jianye with the building of the Zhaoming Palace. Over his sixteen years of rule, he put to death more than forty loyal ministers, including Lu Kai, Wang Fan, Lou Xuan, He Shao, and Wei Yao. This series of political purges caused Eastern Wu to destroy its own talent reserve at the moment it most needed unity, allowing the western Xiling defensive line — which had still been sustained by commanders of Lu Kang's caliber — to collapse rapidly after Lu Kang's death, paving the way for Sima Yan's great expedition against Wu in 279.
Counterfactual Analysis
Had Puyang Xing and Zhang Bu chosen to designate a young ruler governed collectively by a council of designated ministers, Eastern Wu might have maintained a stability similar to the early Sun Xiu period, but the old disease of powerful-minister monopoly could easily have returned. Had they selected a different royal clan member — say, a branch of Sun Xiu's brothers known for an even-tempered character — Eastern Wu's external posture might not have been so frenzied. At a deeper level, Sunhaojiwei truly exposed Eastern Wu's core institutional defect: a lack of an institutionalized succession procedure, with each imperial transition dependent on the ad hoc judgment of a few powerful ministers; and a lack of any effective constraint on imperial power, so that once the wrong man was chosen there was nothing to do but endure the tyranny. This institutional fragility, more than Sun Hao's personal brutality, deserves to be viewed as the root cause of Wu's destruction. As Eastern Wu's final large-scale succession operation, Sunhaojiwei's failure nearly completely locked in the remaining time of the Jiangdong regime.