Who are the celebrities who came from humble origins in ancient times and became big officials by imperial examinations?

This is a lot. The purpose of the imperial examination in Yang Di is to break the monopoly of officialdom by aristocrats caused by the right-wing system and let civilians enter the officialdom. So since then, there have been many civilians who rely on the imperial examination to be big officials. Here are some examples:

Shang Lu, the cabinet minister of Lianzhong Sanyuan in Ming Dynasty,

Lv Mengzheng, Zhang Qixian, Wang Zeng, Song Yao, Song Qi, Wang Yucheng, Cai Xiang, Su Xun, Su Shi, Su Zhe ... were all celebrities of the Song Dynasty who came from humble origins and passed the imperial examinations.

Han Yu and Bai Juyi in Tang Dynasty ...