He formally began his political career in 208 under the Han dynasty's Imperial Chancellor Cao Cao; quickly rising through the ranks. His success in both handling domestic and military affairs, such as in governance and the promotion of agriculture, serving as a capable adviser, repelling incursions and invasions led by Shu and Wu forces, speedily crushing Meng Da's rebellion, and conquering the Gongsun-led Liaodong commandery, all managed to garner him great prestige over the decades. He is perhaps best known for defending Wei from a series of invasions between 231 and 234 led by Wei's rival state Shu.