Dong Yun
While Jiang Wei was aggressively leading Shu forces to attack Wei year after year, the campaigns had taken a toll on Shu's resources but failed to yield any significant gains. In the years after the death of the Shu chancellor Dong Yun in 246, the eunuch Huang Hao came to power and indirectly controlled the Shu government. Huang Hao wanted to remove Jiang Wei from his position of power and replace him with Yan Yu (閻宇), whom he favoured. When Jiang Wei heard about it, he wrote to the Shu emperor Liu Shan to accuse Huang Hao of corruption and treachery, and urge Liu Shan to execute Huang Hao. However, Liu Shan replied, "Huang Hao is merely a minor official. In the past, I hated it when he got into conflict with Dong Yun. Why should you mind him?" Jiang Wei saw that Huang Hao had many supporters in the imperial court and realised that he had gotten himself into trouble when he openly denounced Huang Hao. Hence, he decided to retreat to Tazhong and garrison there instead of returning to the capital, Chengdu.