Meng Da
Meng Da, a former Shu general who defected to Wei in 220, served as the Administrator of Xincheng Commandery (新城郡; in present-day northwestern Hubei) near Shu's northeastern border. Zhuge Liang hated Meng Da for his capricious behaviour and worried that he would become a threat to Shu. Around 227, when he heard that Meng Da had a quarrel with his colleague Shen Yi (申儀), he sent spies to stir up greater suspicions between them and spread news that Meng Da was plotting a rebellion against Wei. Meng Da became fearful and decided to rebel. However, he was stuck in a dilemma after receiving a letter from the Wei general Sima Yi, who was stationed at Wancheng. In the meantime, Sima Yi quickly assembled an army, headed towards Xincheng, and reached there within eight days.