In the third year of Yongxi's reign, Emperor Taizong of the Song Dynasty was eager to show off his martial arts. Zhao Guangyi, Emperor Taizong of the Song Dynasty, took advantage of the opportunity of the new emperor of the Liao Dynasty, and sent three groups of 200,000 troops to the Northern Expedition. In the end, they were defeated. Most of the 200,000 elite imperial troops lost, and the general Yang Ye was captured. , hunger strike to be loyal. The defeat in this battle changed Song's strategic relationship with Liao from offense to defense, which made Song's relationship with Liao finally weak. Name. But at this time, the arrival of a modern person brought a great turning point in history.