Zhao Gao, Qin Dynasty
In the year AD 210, China's first emperor Qingshihuang died of illness in Shaqiu. Eunuch Zhao Gao colluded with Li Si, premier of Qinshihuang, and killed Prince Fu Su and General Meng Tian. They helped Hu Hai gain power. After that, he brutally killed those who held opposing views and also killed his former ally Li Si. Still later he killed Hu Hai; after that the Qin Dynasty fell into chaos.
Zhang Rang, Eastern Han Dynasty
In the later years of the Eastern Han Dynasty, a group of eunuchs, headed by Zhang Rang, dominated the Court. Emperor Ling of the Han called Zhang Rang "father." Zhang and his eunuch always made up various false charges and killed officials along with those holding different views. Their actions finally led to serious disturbances in the later years of the Eastern Han Dynasty.
Liu Teng, Northern Wei Dynasty
Liu Teng came into power by betraying others. Through astute flattery he pleased the Empress Dowager Hu but later on, he murdered her lover, the then prime minister Yuan Yi. At sixty Liu Teng died of illness. After his death, the Empress Dowager Hu regained power. In fury she ordered Liu’s corpse to be exhumed from his grave and thrown into the wildness. She also commanded that all of his 40 and more adopted sons be put to death.
Gao Lishi, Tang Dynasty
Gao was one of the most powerful eunuchs during the Tang Dynasty. He planned and helped Li Longji to kill former Empress Wei and Princess Tai Ping and became the most loyal follower of Emperor Ming during the Tang Dynasty. Gao contributed much to the flourishing period in early Tang Dynasty, hence Gao is considered "conspicuous" among all the eunuchs in ancient China.
Li Fuguo, Tang Dynasty
Li was smart, good at flattering but also very brutal. He flattered the prince, premier, empress and emperor, but when he thought they had no further use to him again, he would kill any of them mercilessly. Eventually, he was torn apart limb from limb and thrown into the wilderness.
Tong Guan, Northern Song Dynasty
After Emperor Huizong acceded to the throne, Tong Guan used everything in his bag of tricks to flatter the emperor and rose quickly. He colluded with Cai Jing to push out other officials in the Court; he appointed their families and friends as officials in different government departments. Tong controlled the military for twenty years, lost many battles with Liao and Jin armies. But the failures didn't cause him to lose any control over the military.
Zheng He, Ming Dynasty
Zheng He was originally surnamed Ma, and later was known as San Bao (Three Treasures). He was a native of Yunnan Province. During the period of the reign of Emperor Chengzu he was castrated and became a eunuch. He was given the surname Zheng by the emperor. He commanded the Ming Dynasty's fleet of immense trading vessels on expeditions – ranging from South Asia, India and Persia, all the way to east Africa. His expeditions are famous even today, and are recognized as great events during the early Ming Dynasty.
Liu Jin, Ming Dynasty
Liu was one of the most famous eunuchs in China’s history. He served Prince Zhu Houzhao when the Prince was young. After the Prince acceded to the throne, he was promoted quickly to become the leading eunuch in the Court. In place of the Emperor, he replied to memorials to the throne and pushed out 56 upright officials. His corruption drove the Ming Dynasty from bad to worse.
Wei Zhongxian, Ming Dynasty
Wei was a former hoodlum and illiterate, but he was highly skilled at the art of flattery. Shortly after he was allowed into the royal palace, Wei was promoted by the eunuch Wang An, giving him the chance to get close to the Emperor Wanli. He maintained an intimate relationship with the nanny of the emperor’s grandson Zhu Youjiao, who later became Emperor Xizong. After Zhu Youjiao acceded to the throne, Wei seized power and killed Wang An; he also jailed many innocent people. He led the monarchy manipulated by eunuchs to the peak.
Li Lianying, Qing Dynasty
Li Lianying spent 52 years in the royal palace. He was the most favored servant of the Empress Dowager Cixi. Li was the highest ranked, most powerful, and richest eunuch with the longest tenure of service throughout the Qing Dynasty. Both his servility to his master and his brutality over other officials were unsurpassable. Li interfered with all state affairs. Officials in and out of the palace scurried to curry his favor.
(China.org.cn December 7, 2007)