Background
The Yidaizhao incident occurred in the third year after Cao Cao's pattern of "holding the emperor hostage to command the lords" had taken firm shape. In the first year of Jian'an (196), Cao Cao escorted Emperor Xian to relocate the capital to Xu Chang, after which practical power over the court passed to the Office of the Excellency over the Masses; Emperor Xian became a political symbol. Yet within the palace there remained a cohort of "old Han ministers" and imperial relatives — Empress Fu, Fu Wan, Dong Cheng, Zhong Ji, and others — who retained a genuine political stake in the fate of the Han dynasty. From an institutional-history perspective, this two-layer structure of "puppet emperor plus surviving imperial kinsmen" was inherently unstable: once those kinsmen sensed that Cao Cao intended to pursue the path of "Han-Wei dynastic replacement," they would inevitably make a final resistance in the name of "restoring the sovereign" [c:17659][c:17660]. The fourth year of Jian'an was the critical juncture — that year Cao Cao had already pacified Lv Bu and subdued Zhang Xiu, and external threats had concentrated along the Yuan Shao front; his purge of Xudou's internal opposition accelerated as well, with actions such as killing the Counselor Zhao Yan and forcing out Grand Commandant Yang Biao causing the officials to "tremble in fear" [c:17657]. The conspiracy of Dong Cheng and others took shape in this atmosphere of "seeing the window of opportunity closing."
Principal Figures
At the center of the event was Dong Cheng, General of Chariots and Cavalry — nephew of Empress Dowager Dong Taihou of Emperor Ling, and thus the emperor's "maternal uncle" (in fact his father-in-law) [c:17656]. He was one of the highest-ranking imperial kinsmen at court, bore an old merit for rescuing the emperor during the flight from the western capital, and harbored genuine political feeling for the Han house. Liu Bei at this moment was a guest sojourner in Xudou in an awkward position: he was both the "Governor of Yuzhou" honored by Cao Cao and the publicly acknowledged "imperial uncle," and he knew perfectly well where his ceiling within Cao Cao's system lay. During Qingmeizhujiulunyingxiong, Cao Cao's remark "Today's heroes under heaven are none but you and I, my lord" [c:17656] caused Liu Bei to "drop his chopsticks" — at that moment Liu Bei understood he could no longer remain in Xudou. Among the other participants, Zhong Ji, Wu Shuo, Wang Zifu, and Wu Zilan were knowing conspirators of lesser political weight but provided the manpower the plot required [c:17656][c:17664]; Ma Teng represented potential western aid and theoretically could threaten Cao Cao's rear from the west; Fu Wan was the father of Empress Fu Hou, and the novel depicts the entire Yidaizhao scheme as having been devised by Fu Wan [c:17660], giving the conspiracy an internal palace planner.
Core Issue
The central question this unexecuted coup d'état sought to answer was a very specific one: with Cao Cao already controlling central military affairs and administration, yet not having publicly usurped the throne, did the opposition still possess any legitimate and effective means of resistance? Dong Cheng and his confederates chose to "launch a coup in the form of a secret imperial edict," essentially trying to press "Han dynastic legitimacy" against "military hegemon power." This approach had two fundamental weaknesses. First, the authenticity of a secret edict could not be verified by the outside world: once Cao Cao controlled the flow of information from the palace, the document could be acknowledged only after the coup had already succeeded. Second, the participants' combined strength was nowhere near sufficient to confront Cao Cao's imperial guard troops in Xudou in direct battle — the "household retainers of five families" that Dong Cheng could mobilize totaled no more than a thousand or so men [c:17673]. The entire plan could only be launched at the instant Cao Cao personally departed on campaign and Xudou's defenses relaxed; but Cao Cao ran his army with extreme strictness, and Xudou was never truly "lightly garrisoned." From a political-science standpoint, this was a textbook attempt to "deploy legitimacy resources against power resources" — and when the legitimacy symbol itself (the emperor) was also controlled by the adversary, such opposition was almost certainly doomed to fail.
Political Consequences
The reckoning after the plot was exposed was thorough. In the first month of Jian'an year five, Dong Cheng and the others were all executed along with their kin and families [c:17655]; Cao Cao then "led his forces east to attack Liu Bei," ignoring the fact that Yuan Shao was still mobilizing forces in the north [c:17655]. When his generals worried that Yuan Shao might exploit the exposed rear, Cao Cao's reply was "Liu Bei is a hero among men; if I do not strike him now, he will certainly become a future calamity" [c:17655] — this remark sealed Liu Bei's fate for the following twenty years: from then on Cao Cao regarded him as "a hero who must be dealt with," and Liu Bei could no longer survive within Cao Cao's system. Liu Bei fled in defeat to Yuan Shao, while Guan Yu, trapped in Xiapi with his forces broken, surrendered [c:17655] — this is the true starting point of the sub-event "Guanyujiangcao." On the longer historical scale, the failure of the Yidaizhao marked the suppression of the last organized internal effort to restore the Han; from then on Cao Cao could push forward his three-step program of "enfeoffed Duke of Wei — elevated King of Wei — replace the Han" without any need to look over his shoulder at home. In the twentieth year of Jian'an, Empress Fu Hou again attempted to contact outside allies through her father Fu Wan, resulting similarly in "exposure, Fu Wan's execution, and the empress's deposition" — this chain of events is structurally almost identical to the Yidaizhao, yet its probability of success was even lower because Cao Cao had by then far more completely controlled the palace apparatus.
Counterfactual Analysis
Two counterfactuals in the retrospective analysis are most worth developing. The first: had Dong Cheng and his confederates chosen "patient long-game" — not launching a coup but instead gradually infiltrating Xudou's palace guards and local garrisons, waiting for Yuan Shao's southward push as the moment for internal-external coordination — what would the outcome have been? This is theoretically a more robust path, but the operational difficulty was immense: Dong Cheng and his associates lacked military command experience, the Xudou palace guard was a monolithic instrument in Cao Cao's hands, and sustained infiltration had almost no opening. Even so, moving slowly would always have been better than moving fast — their real blunder was exposing the conspiracy before any outside ally had arrived (the household slave Qin Qingtong's denunciation was merely the surface; the true root cause was too many participants and insufficient operational security) [c:17674]. The second counterfactual: had Liu Bei not accepted Dong Cheng's alliance at the outset — maintaining the posture of a purely neutral "guest general of Cao Cao" — could he have survived within Cao Cao's system? From the Qingmeizhujiulunyingxiong conversation it is clear that Cao Cao had already placed Liu Bei in the category of "the only man I can call a hero alongside myself" [c:17656] — meaning his reckoning with Liu Bei was only a matter of time, independent of the Yidaizhao; the Yidaizhao at most accelerated the reckoning rather than creating it. Liu Bei's departure on the pretext of requesting to intercept Yuan Shu was therefore "the better of two bad options" — the probability of being killed by staying was far higher than the probability of escaping by seizing the chance. Understanding this explains why, from San Guozhi to San Guo Yanyi, all narrators treat the Yidaizhao as Liu Bei's true starting point of independent founding: before it he was a senior guest general within Cao Cao's system; after it he was the publicly acknowledged "orphan of the Han house," and there was no going back.