 In 599, Emperor Wen made him the head of the legislative bureau ("Neishi Sheng", 內史省), one of the five main bureaus of government.In 600, due to Yang Guang's machinations, Emperor Wen deposed Yang Jian's uncle Yang Yong the Crown Prince, and created Yang Guang crown prince instead.In 601, Yang Jian was made the commandant at Yang Province (揚州, roughly modern Yangzhou, Jiangsu), to replace his father Yang Guang.