After Gao Wei was created crown prince in 562, his father Emperor Wucheng set up a guard corps commanded by 20 officers.
Han was particularly powerful after the general Hulü Guang was falsely accused of treason and executed in 572, and he, Mu, and Gao Anagong were referred to as the "Three Nobles," controlling the government together, and they were later blamed for the deterioration of Northern Qi.
When the Chen dynasty attacked and captured the region between the Yangtze River and Huai River in 573, including the important city Shouyang (壽陽, in modern Lu'an, Anhui), Han and Mu were gambling when news of Shouyang's fall arrived and not willing to stop despite the bad news.
Further, during the Chen campaign, when Cui and Zhang, along with several other officials, including Feng Xiaoyan (封孝琰), Liu Ti (劉逖), Pei Ze (裴澤), and Guo Zun (郭遵), submitted a joint petition trying to persuade Gao Wei not to visit the secondary capital Jinyang (晉陽, in modern Taiyuan, Shanxi), on account that such a visit might be misinterpreted by the people as flight, it was Han who suggested that those civilian officials were, in effect, committing treason, and should all be killed.
Han subsequently fled with Gao Wei south of the Yellow River and was one of the few officials who did not surrender to Northern Zhou.