The Battle of Xin Castle or alternatively known as the Xincheng Rebellion was a conflict between Meng Da, who had recently defected to Shu, and Sima Yi of Wei. Zhuge Liang attempted to collaborate with Meng into making joint attacks to Wei's western provinces, but Sima Yi defeated Meng Da before he could join up with Shu. In the novel, Xu Huang is also killed in this conflict.