Wei Kingdom (220-266) was one of the separatist regimes in the Three Kingdoms era, and the most powerful country amongst the Three Kingdoms, which dominated China from 220 to 280. The Yellow River Basin under the control of Wei was the main grain producing area. The territory of Wei developed substantially during Cao Cao’s time, the kingdom only crystalized when Cao Pi declared himself Emperor, occupying the Central Plains and the entire northern region of China. Wei is rich in materials, abundant in food and grass, leading to a large population, not to mention a strong wall for defense. Wei’s strength is far superior to that of Shu and Wu. In addition, Cao Cao once held the Emperor hostage and issued orders in the name of the Emperor. This put Wei the center of politics.