东山再起：东晋谢安退职后在东山做隐士，后来又出任要职
Xie An, an official of the Eastern Jin Dynasty, resigned from office and lived in the Dongshan Mountains as a hermit, and later took an important post again;
（比喻）失势之后，重新恢复地位
(of one who once lost his power) resume one's former position; stage a comeback; return to power
