To make matters worse, Cao Pi and his officers were uneasy about Sun's titles and ranks (such as King of Wu) because it was quite inappropriate since they were considered a vassal state under Wei.
However Sun Quan declined this request, and later apologised to Cao Pi, stating his son was still very young and vulnerable in his health to be away from his home and family.
Diplomatic ties between the two continued to sour until finally, Cao Pi decided to attack Sun Quan.
[8] In response, Sun Quan put Lü Fan in command of five armies to resist Cao Xiu; Zhuge Jin, Pan Zhang and Yang Can (楊粲) were dispatched to relieve the siege on Nan Commandery which was being defended by Zhu Ran while Zhu Huan defended the fortress of Ruxu from Cao Ren.
[11] When Cao Xiu, Zhang Liao and Zang Ba launched their attack, Lü Fan, along with Xu Sheng, Quan Cong and Sun Shao, led naval forces to resist the enemy at Dongkou.
[12] By this time it was early 223, and Cao Xiu ordered Zang Ba to attack Sun's small stronghold at Xuling.
Nonetheless, Cao Xiu eventually managed to gain the advantage as Lü Fan's forces were beginning to struggle.
[14] The battle is a playable stage in the seventh instalment of Koei's Dynasty Warriors video game franchise.
In the stage, though Cao Pi surrenders, later the game reveals in a following Wu cinematic clip that Sun Quan was dreaming.