 In 578, Emperor Wu died, and the crown prince Yuwen Yun became emperor (as Emperor Xuan).In spring 579, Emperor Xuan established four new senior advisor posts, and he made, as those four, his uncle Yuwen Sheng (宇文盛) the Prince of Yue, Yuchi Jiong, Li Mu (李穆) the Duke of Shen, and Yang Jian the Duke of Sui (and his father-in-law, as the father of his wife Yang Lihua).He also made Yuchi in charge of the region around Xiang Province (相州, roughly modern Handan, Hebei) -- effectively, the region north of the Yellow River.