Xu Jie was the head of the cabinet after Yan Song.
After Zhang Juzheng, Shen Shixing was the chief assistant of the cabinet.
After Zhang Juzheng, the cabinet chiefs were Yang Shiqi, Yang Rong, Gao Gong, Xu Jie, Shen Shixing, Ye Xianggao, and Yang Tinghe.
After Shen Shixing, the chief assistant of the cabinet was Wang Xijue.
There were many candidates for the chief assistant of the Chongzhen cabinet, including Shi Yulai, Li Guo, Lai Zongdao, Zhou Daodeng, Han Yulai, Li Biao, Cheng Jiming, Zhou Yanru, Wen Tiren, Zhang Zhifa, Kong Zhenyuan, Liu Yuliang, Xue Guoguan, Fan Fucui, Zhang Sizhi, Chen Yan, Jiang Dejing, and Wei Zaode. However, because the information provided in the search results was not detailed enough, it was impossible to determine the specific time and achievements of each person as the cabinet chief. Therefore, he could not give an accurate answer.
Xia Yan was Yan Song's previous cabinet chief.
After Yan Song, the chief of the cabinet was Xu Jie. Xu Jie succeeded the cabinet chief after the fall of Yan Song and held this position until the death of Emperor Jiajing. When Xu Jie was the chief assistant of the cabinet, he had drafted the posthumous edict of Emperor Jiajing together with Zhang Juzheng, helping the officials who had been wrongly sentenced to restore their original positions, and distributing the fields occupied by King Jing to the people for cultivation, so he was praised by the people. However, in his later years, Xu Jie indulged his children in robbing the people's fields and covered up their illegal acts, causing him to gradually lose the hearts of the people. Xu Jie did not receive the praise of the people after his death because his actions in his later years lost the support of the people.
Yan Song served as the chief assistant during the Jiajing period of the Ming Dynasty, but the given search results did not mention the specific time he served as the chief assistant. Therefore, I don't know exactly when Yan Song became the chief.
Zhang Juzheng became the chief assistant of the cabinet in the sixth year of Longqing (1572).
During the Jiajing period, the cabinet chiefs were Zhang Cong, Xia Yan, Yan Song, Xu Jie, Yang Tinghe, Jiang Mian, Mao Ji, Fei Hong, Huanghuai, Xie Jin, Hu Guang, Yang Rong, Yang Shiqi, Huang Jin, Li Chunfang, etc. Among them, Zhang Cong had the best political achievements among the chief assistants during the Jiajing period. He was praised as "In the end of the Jiajing period, there was no one like Fujing (Zhang Cong) among the physiognomists." Xia Yan stood out in the Great Ceremony and became the chief assistant of the cabinet. Yan Song was a powerful official and had once served as the chief assistant of the cabinet. Xu Jie was a famous official of his generation, but he did not stand up to support Xia Yan after he was framed and worked with Yan Song for more than ten years. Yang Tinghe, Jiang Mian, Mao Ji, Fei Hong, Huang Huai, Xie Jin, Hu Guang, Yang Rong, Yang Shiqi, Huang Jin, Li Chunfang, and others had also served as cabinet chiefs during the Jiajing period.
Xu Jie and Li Chunfang were the two chiefs behind Yan Song. Xu Jie took over as the chief assistant of the cabinet after Yan Song abdicated, eliminating the maladministration during Yan Song's reign, and recommended Gao Gong and Zhang Juzheng to enter the cabinet. Xu Jie was diligent in government affairs and loved talents, which laid the foundation for the Wanli New Deal. Li Chunfang became the chief of the cabinet after Xu Jie, but he was mediocre and retired a few years after being suppressed by Gao Gong.