more—and he persuaded them that the high level officials were intending harm to them and that they could only trust him. Gao Wei thus issued an edict rebuking Gao Rui. When Gao Rui nevertheless entered the palace to try to pressure Empress Dowager Hu and Gao Wei to remove He Shikai. Empress Dowager Hu, instead, arrested Gao Rui and had the guard commander Liu Taozhi (劉桃枝) strangle Gao Rui. Thereafter, He Shikai's power went unchecked. The other favorite associates of Gao Wei included Gao Wei's wet nurse Lu Lingxuan and her son Mu Tipo, as well as Zu Ting. In summer 570, Gao Wei's concubine Consort Mu Sheli gave birth to his first son, Gao Heng, and Gao Wei declared a general pardon. Lady Lu, who was also Consort Mu's adoptive mother, wanted Gao Heng to eventually be crown prince and emperor, but was afraid that Empress Hulü would oppose the plan, so she gave Gao Heng to Empress Hulü for her to raise. In winter 570, Gao Wei created Gao Heng crown prince. During much of Emperor Wucheng's and Gao Wei's reign up to this point, rival Northern Zhou had gradually encroached on Northern Qi territory, making minor gains on the borders. In winter 570, Hulü Guang launched a counterattack and captured significant amounts of territory north of the Fen River (汾水, flowing through modern Linfen, Shanxi). He then also defeated Northern Zhou troops at Yiyang (宜陽, in modern Luoyang, Henan). On his way back to the capital Yecheng (鄴城, in modern Handan, Hebei), Gao Wei ordered his troops demobilized even though many of the soldiers had not received rewards. However, he received an order to demobilize his troops. Hulü Guang submitted a secret petition to Gao Wei, requesting the emperor to send imperial messengers to the army to honor the soldiers. Gao Wei did not act immediately, however, and the army approached Yecheng without receiving any words from the emperor. Gao Wei was displeased that Hulü Guang brought the army close to the capital, and he summoned Hulü to the palace before sending messengers to honor the soldiers and demobilizing them. Later in 571, Gao Wei's brother Gao Yan, now the Prince of Langye, angry at the hold that He Shikai had on power, killed him, and further mobilized his troops to consider seizing power and killing Lady Lu and her son Mu Tipo, who had also become