"Eunuch faction" (yandang 閹黨) was the designation for groups of court officials siding with the chief eunuchs in the battle for power at the imperial court of the mid- and later Ming period 明 (1368-1644). Eunuchs like Wang Zhen 王振 (d. 1449), dominating the politics of Emperor Yingzong 明英宗 (r. 1435-1449 and 1457-1464), or Wang Zhi 汪直 (d. 1487), controlling Emperor Xianzong 明憲宗 (r. 1464-1487), needed state officials of the central government for support.
The largest group of official-supporters formed up during the reign of Emperor Wuzong 明武宗 (r. 1505-1521), when the chief eunuch Liu Jin 劉瑾 (1451-1510) was the informal regent of the court. Under his power, the "Eight Tigers" (ba hu 八虎), a group of eunuchs, spied out and terrorized the court officials. Yet the Grand Academicians (daxueshi 大學士) Jiao Fang 焦芳 (1435-1517) and Liu Yu 劉宇 (jinshi degree 1472), Minister of Personnel (libu shangshu 吏部尚書) Zhang Cai 張綵 (jinshi degree 1490) and Minister of War (bingbu shangshu 兵部尚書) Cao Yuanjin 曹元錦, as well as the commanders of the Brocade Guards (jinyihui 錦衣衛, see changwei 廠衛), Yang Yu 楊玉 (jinshi degree 1433) and Shi Wenyi 石文義, helped Liu Jin to gain and keep his power over the emperor and the court. They supported him in purging officials daring to criticize the tyrant eunuch, accepted bribes, and intimidated and had incarcerated anyone opposing them, even dukes, princes and persons of merit.
During the reign of Emperor Xizong 明熹宗 (r. 1620-1627), Wei Zhongxian 魏忠賢 (1568–1627) was the powerful eunuch, who was supported by quite a few court officials. More than thirty persons came from the eunuch staff (neijian 內監) in the Inner Palace, like Wang Tiqian 王體乾, Li Chaoqian 李朝欽 or Wang Chaofu 王朝輔, and at the outer court Wei found supporters in the Grand Academicians Gu Bingqian 顧秉謙 (b. 1550) and Wei Guangwei 魏廣微 (d. 1627). Yet he was also backed by famous writers like Cui Chengxiu 崔呈秀 (1571-1627), Tian Ji 田吉, Wu Chunfu 吳淳夫 (1577-1627), Li Kuilong 李夔龍 (d. 1629) and Ni Wenhuan 倪文煥 (d. 1627), known as the "Five Tigers" (wu hu 五虎).
Another group was called the "Five Panthers" (wu bao 五彪), namely Tian Ergeng 田爾耕, Xu Xianchun 許顯純 (d. 1628), Sun Yunhe 孫雲鶴, Yang Huan 楊寰 and Cui Yingyuan 崔應元. All of them readily executed Wei Zhongxian's orders to purge his opponents. The tyrant was able to rely on the support of many more, as the "ten dogs" (shi gou 十狗), the ten grandsons (shi sun'er 十孩兒) or the fourty grandsons (sishi sun 四十孫). They were scattered all over the empire and often occupied high positions in the military and civilian administration. Without the support of these officials, Wei Zhongxian would not have been able to usurp so much power, to enrich himself, and to destroy all his enemies, mainly those of the Donglin Faction (donglin dang 東林黨), like Gao Panglong 高攀龍 (1562-1626), Yang Lian 楊漣 (1572-1625), Zhou Shunchang 周順昌 (1584-1626), Wei Dazhong 魏大中 (1575-1625) and Gu Dazhang 顧大章 (1567-1625).
It was Cui Chengxiu who drafted the files for the three paradigmatic cases (sanchao yaodian 三朝要典) by which Wei bolstered his position and condemned his antagonists. When Wei was finally arrested and executed, the Chongzhen Emperor 崇禎 (r. 1627-1644) issued six edicts on treason (ni'an 逆案), and according to the files, more than 260 persons of the eunuch faction were tried, on the ground of the first Ming emperor's edict that eunuchs were not allowed to interfere into court politics.
|Jiao Fang 焦芳 (app. Liu Yu 劉宇, Cao Yuan 曹元)|
|Zhang Cai 張彩 (app. Han Fu 韓福, Li Xian 李憲, Zhang Long 張龍)|
|Gu Bingqian 顧秉謙 and Wei Guangwei 魏廣微 (app. Huang Liji 黃立極, Shi Fenglai 施鳳來, Zhang Ruitu 張瑞圖, Lai Zongdao 來宗道, Yang Jingchen 楊景辰)|
|Cui Chengxiu 崔呈秀 (app. Wu Chunfu 吳淳夫, Ni Wenhuan 倪文煥, Tian Ji 田吉, Li Kuilong 李夔龍; and the text of the imperially endorsed Qinding ni'an 欽定逆案)|
|Liu Zhixuan 劉誌選 (app. Liang Menghuan 梁夢環, Liu Shao 劉詔, Shao Fuzhong 邵輔忠, Sun Jie 孫傑)|
|Cao Qincheng 曹欽程 (app. Shi Sanwei 石三畏, Zhang Na 張訥, Lu Chengqin 盧承欽, Men Kexin 門克新, Liu Hui 劉徽, Zhi Ting 智鋌)|
|Wang Shaohui 王紹徽 (app. Zhou Yingqiu 周應秋)|
|Huo Weihua 霍維華 (app. Xu Dahua 徐大化, Li Fan 李蕃, Li Lusheng 李魯生, Li Hengmao 李恆茂)|
|Yan Mingtai 閻鳴泰 (app. the text of Wei Zhongxian's proclamation to his own shrine, Shengci zhi jian 生祠之建)|
|Jia Jichun 賈繼春|
|Tian Ergeng 田爾耕 (app. Xu Xianchun 許顯純, Cui Yingyuan 崔應元, Sun Yunhe 孫雲鶴, Yang Huan 楊寰)|