Background
From the perspective of cultural history, the Tushanyuesanshi is an exceptionally rare case of "conditional surrender" in ancient Chinese military history. In the fifth year of Jian'an (200), Cao Cao launched his eastern campaign into Xuzhou; the gates of Xiapi were opened from within by soldiers who feigned surrender, and Cao's troops entered the city under cover of fire to cut off Guan Yu's forces [c:16524]. Guan Yu, with his remnant soldiers trapped on Tushan, "charged down the hill time and again through the night, only to be driven back each time by a storm of arrows" [c:16525], and was in physical terms already in a situation of certain death. This background is important because it established the objective preconditions for the three-clause compact: Guan Yu could not break out, was unwilling to die pointlessly, and yet could not accept a simple "surrender" — this threefold predicament provided the soil for an unusually specific, ritualized compact that transformed "surrender" into "temporary sojourn under another's roof." That Zhang Liao, as an old friend, rode alone up the hill to persuade him was also a key personnel condition — without that layer of private trust, no negotiation of terms could ever have begun [c:16525].
Content of the Pledge
Each of Guan Yu's three clauses addressed a specific dimension of his relationship with Liu Bei with precision. The first clause — "I surrender only to the Han Emperor, not to Cao Cao" [c:16527] — cut at the ideological level between "the object of surrender," separating Cao Cao's role as chancellor from his role as the voice of the Han emperor, allowing Guan Yu to maintain nominal loyalty to the Han house rather than to Cao Cao personally. Cao Cao's response — "I am the Han chancellor; the Han and I are one" [c:16528] — accepted this clause through a form of political equivalence. The second clause — "At the two sisters-in-law's quarters, please provide the stipend of the Imperial Uncle in full; no one of any rank is to be permitted at the gate" [c:16527] — at the ethical level protected the safety and dignity of Liu Bei's family, avoiding the double moral stain of "surrendering while also abandoning one's elder brother's wife"; Cao Cao not only complied but "doubled the stipend beyond what the Imperial Uncle received" [c:16528], actually raising the material treatment of Liu Bei's family. The third clause — "The moment I learn of the whereabouts of Imperial Uncle Liu, no matter how many thousands of li, I shall at once take my leave" [c:16527] — at the substantive level preserved the path of return to Liu Bei; this was the most difficult and most decisive of the three clauses. Cao Cao was initially unwilling to promise it, and only accepted after Zhang Liao invoked the "Man of the Nation" argument from Yurang — that generous treatment could redirect a man of integrity's loyalty — [c:16528]. Taken together, the three clauses constituted a rare "conditional adherence compact" in the disorder of the late Han.
Subsequent Impact
The political effects of the Tushanyuesanshi far exceeded its literary significance. For Guan Yu, this event established the core narrative of his image of "righteousness" — able to uphold his principles even in defeat, able to fulfill his obligations after adhering (the killing of Yan Liang and Wen Chou at Baima), and finally, on learning of Liu Bei's whereabouts, relinquishing his seal, returning all the gifts, and journeying a thousand li to find his brother. This pattern of behavior — serving the current lord first, then returning to the original one — was in itself contradictory by the value system of late Han scholars, but through the form of the three-clause compact it was legitimized and ritualized, and from that point became the benchmark example of China's traditional concept of "loyalty and righteousness." For Cao Cao, although this affair cost him on the third clause, he gained Guan Yu's critical contribution at the Battle of Baima and a powerful demonstration effect on other Han loyalist generals — the public praise "a man who serves his lord without forgetting his roots is truly a righteous man of the realm" [c:16531] was Cao Cao's deliberate effort to shape Guan Yu into a "benchmark of loyalty" within his own camp. Viewed over a longer arc, the three-clause compact also indirectly reinforced the cohesion of Liubeijituan — the legend of Guan Yu's solitary thousand-li ride, as it spread among the people, became symbolic proof that "Liu Bei's team is indivisible," and this narrative capital repeatedly provided Shuhan with legitimacy support throughout Chibi, the entry into Shu, and the northern campaigns. From the echoes in cultural history, the model of "conditional adherence" pioneered by the Tushanyuesanshi has almost no true successors in ancient Chinese political history — it required both parties to possess considerable political maturity, considerable mutual trust, and a shared commitment to "righteousness." The simultaneous presence of all three was a historical coincidence, and it is the fundamental reason this compact has been transmitted and celebrated across the centuries.