Liu Bei and Guan Yu's sworn brother relationship

Xuande and Guan Yu’s sworn-brother relationship is a governing bond of the novel, not merely a statement of affection: it gives Guan Yu a standard by which to judge service, protection, and political loyalty, even when separation puts the oath under strain. His temporary submission to Cao Cao is framed as an effort to preserve Xuande’s household and his ability to return; once he learns Xuande is alive, he risks departure to reunite with him. The relationship also reaches beyond private loyalty, since the brothers’ shared vow to uphold the Han is later invoked in disputes over territory and military action.

The oath as a standard of duty

When Guan Yu is surrounded after Xuande’s defeat, Zhang Liao argues that dying rather than submitting would violate the brothers’ joint vow. Xuande might survive and need his help; Xuande’s wives, entrusted to Guan Yu, would be left without his protection; and the sworn purpose of defending the Han would be abandoned. Submission, Zhang Liao reasons, would preserve Guan Yu’s life and allow him to remain useful to both his brother and their cause.

Guan Yu accepts the argument only on conditions that preserve the meaning of his allegiance. He will submit to the emperor, not to Cao Cao; he will retain authority over the protection of his sisters-in-law; and, once he discovers Xuande’s whereabouts, he must be free to go to him. The terms distinguish temporary service from a transfer of loyalty. Cao Cao’s eventual acceptance creates the promise on which Guan Yu later relies.

Separation and guarded service

While in Cao Cao’s custody, Guan Yu takes responsibility for transporting Xuande’s wives and rides beside their carriage. When Cao Cao arranges for them and Guan Yu to share a room, Guan Yu instead stands guard outside through the night. The episode makes protection an active obligation: his physical proximity to the household does not become a claim upon it, and Cao Cao recognizes the restraint as evidence of Guan Yu’s virtue.

Cao Cao gives Guan Yu Red Hare, a horse capable of covering a thousand miles in a day. Guan Yu values the gift because it would let him reach Xuande quickly once he knew where his brother was. The horse thus becomes a practical means of fulfilling the reunion that remains the priority of his service. Asked why he will not abandon Xuande, Guan Yu recalls the brothers’ vow and says that even if Xuande were dead, he would serve him in the underworld. He nevertheless acknowledges a debt to Cao Cao for generosity and kindness, a debt he expects to repay through one great service rather than through permanent allegiance.

That tension sharpens when a smuggled letter from Xuande asks why Guan Yu appears to have abandoned their oath. Guan Yu weeps and writes back that he entered Cao Cao’s service to protect the two women, not to forget his brother. Now that he knows Xuande is alive and with Yuan Shao, he intends to escort the women to him. Guan Yu repeatedly seeks Cao Cao to claim the promised right to leave, but is told each time that Cao Cao is absent. Recognizing the evasion, he leaves a farewell letter and packs up the gifts he received so that none can accuse him of taking them improperly.

Departure and reunion

Guan Yu departs on Red Hare with his Green Dragon sword, escorting the two women in their carriage through the north gate. He leaves Cao Cao’s gifts behind, making his departure consistent with the terms he had set. On the journey, Zhou Cang, a former Yellow Headband rebel turned robber, recognizes Guan Yu and asks to join him. The procession is therefore not only a family escort: it also gathers a new follower around Guan Yu’s reputation and purpose.

At Gucheng, Guan Yu learns that the fierce warrior controlling the city is Zhang Fei. His expectation of a warm welcome is interrupted by suspicion: Zhang Fei doubts that Guan Yu has remained true to Xuande. When Cai Yang arrives and accuses Guan Yu of murder, Guan Yu kills him before Zhang Fei can complete one roll of the war drums. A captured officer then reveals that Cao Cao had ordered an attack on Runan, not the capture of Guan Yu; Cai Yang had turned their accidental meeting into a pretext for confrontation. Zhang Fei questions the prisoner until he accepts that Guan Yu has told the truth.

The brothers enter Gucheng together and spend the day recounting what has happened during their separation. Their reunion is marked by sacrifice to Heaven and Earth with an ox and a horse and by celebration. Guan Ping and Zhao Zilong also join the company, adding to the joy of the gathering. The narrative’s image of the men scattered like severed limbs gives the reunion its force: the oath is made visible again through the restoration of a divided group.

Loyalty, politics, and continued conflict

The bond continues to operate as a public political claim. When Zhuge Jin presses Guan Yu to surrender territory, Guan Yu refuses, declaring that he is defending Han lands and invoking the vow made with Xuande in the peach orchard to uphold the Han. Xuande subsequently tells Zhuge Jin to return to Wu with the promise that the territory may be returned after his conquests in Shu are finished and Guan Yu is invited to govern there. Guan Yu’s refusal and Xuande’s proposed settlement expose a strain between the brothers’ shared allegiance and the immediate demands of diplomacy, without erasing their bond.

Their partnership also frames military decisions. After Cao Cao and Sun Quan form a pact, Xuande consults Kong Ming, who proposes that Guan Yu attack Fancheng to disrupt the alliance. Guan Yu proceeds with the campaign. The decision places the sworn brother in service to Xuande’s wider strategy, while the earlier history of their vow explains why loyalty to the Han and to the brotherhood can be invoked together. Later, Xuande’s accession as king in late AD 219 formalizes the standing of Guan Yu and their fellow commanders: Guan Yu is named one of the Five Tiger Generals.

Across these episodes, the relationship is tested not by a single repudiation but by separation, suspicion, gifts, promises, and competing political responsibilities. Guan Yu’s service to Cao Cao remains conditional; his protection of Xuande’s household and his return to Xuande keep the oath intact. At Gucheng, reunion turns an asserted obligation into a renewed collective bond, while later appeals to the peach-orchard vow show that the brothers’ pledge remains an active source of identity and political justification.