After the death of his father, Li Yuanhao (Emperor Jingzong) in 1048, Yizong assumed the throne at the age of one, but most of the power laid in the hands of his mother the Empress Dowager.
In 1049, the Liao dynasty attacked the Western Xia and forced it to become a vassal state.
In 1061, Yizong's uncle and cousin plotted against him, so he had them executed and assumed direct control of the Western Xia.
Yizong began to attack the Northern Song dynasty and raided their villages.
In later years, Yizong began to improve diplomatic relationships with the Northern Song and Liao dynasties.