Empress Lü Zhi
After Zhang Ao was falsely accused of conspiring against the throne, Ruyi replaced him as prince or king of Zhao in 198BC. The next year, he received Chen Xi as his chancellor of the realm but Chen soon launched a rebellion at Julu (within present-day Pingxiang County, Hebei); he was defeated in battle but remained at large for several years. When Liu Bang fell ill in early 195BC, he found that Empress Lü Zhi was plotting to kill Ruyi in order to eliminate a rival claimant to the imperial throne; Liu Bang at one point had considered making Liu Ruyi crown prince, but eventually did not do so after advice from various officials, including Shusun Tong, Liu Ying's teacher. The emperor then appointed Zhou Chang as chancellor in Zhao to protect the prince from his stepmother.