Sun En 孫恩

Sun En 孫恩 (d. 402) was a rebel during the Eastern Jin period 東晉 (317-420). His uprising is often mentioned alongside that of Lu Xun 盧循 (d. 411) which was a continuation of Sun's rebellion. Both of these uprisings were particularly significant and contributed to the weakening of the Jin government.

Sun En, courtesy name Lingxiu 靈秀, hailed from Langya 瑯邪 (present-day Linyi 臨沂, Shandong) and belonged to a family of lower elites. The Sun family adhered to the Daoist Five-Pecks-of-Grain Sect (wudoumi dao 五斗米道), and one of Sun En's uncles, Sun Tai 孫泰 (d. 398), was even a master of this creed.

The Eastern Jin dynasty was founded after the evacuation of the northern capital, Luoyang 洛陽, which was invaded and destroyed by non-Chinese peoples. As an exile government, the Eastern Jin dynasty relied heavily on close cooperation with the local elites of southeast China, to whom the Jin court granted many liberties. In the late fourth century, the growing population – comprising both locals and northern immigrants – led to an increasing division of land, with the Jin dynasty itself controlling progressively less territory. Consequently, the burden of tax payment and labour service primarily fell upon the region between the capital, Jiankang 建康 (today's Nanjing 南京, Jiangsu), and Sanwu 三吳 (around present-day Suzhou 蘇州, Jiangsu), while the prominent families (menfa 門閥) in the south were relieved of these responsibilities. The lower social strata included slaves and client farmers (dianke 佃客), many of whom held the status of bondservants to landowners.

The spark that ignited Sun En's rebellion was a law promulgated in 399. It aimed at the liberation of slaves (mian nu wei ke 免奴為客) with the intention of making more people liable for military service. While slaves were not obliged to serve, bondservants and free men had to serve in the army. The law was also disliked by landowners, as they would lose dependent individuals to serve on their estates and in their residences.

In 397, when Wang Gong 王恭 (350-398), the regional inspector (cishi 刺史) of the province of Yanzhou 兗州, Sun Tai planned to join the movement, but he was killed before he could take action. Sun En fled to the Zhoushan Islands 舟山群島 off the coast of today's Ningbo 寧波, Zhejiang, and began to gather escaped farmers. In 399, he ferried over to the mainland with more than 100 followers and attacked the city of Shangyu 上虞, followed by Guiji 會稽 (today's Shaoxing 紹興, Zhejiang), where he killed Wang Ningzhi 王凝之, the Administrator of the Household (neishi 內史) of the Prince of Guiji. Sun's movement quickly attracted farmers and bondservants, as well as discontented members of the elite. With these supporters, he was able to raise eight commanderies in southeast China against the Jin court. Historians say that, within ten days, the rebellion drew several hundred thousand supporters. He adopted the title of General Conquering the East (zhengdong jiangjun 征東將軍) and called his army Long-Living Men (shangshengren 長生人). The rebels killed representatives of the government throughout the region, and there were even rebellious activities in Jiankang.

The Jin court thereupon sent out Sima Daozi 司馬道子 (364-403), Sima Yuanxian 司馬元顯 (382-402), Xie Yan 謝琰 (d. 400) and Liu Laozhi 劉牢之 (d. 402) to attack Sun from various directions. Sun then ordered 200,000 men and women to withdraw to the islands. A year later, the rebels again landed on the mainland and took Yuyao 余姚 and Shangyu. In the battle of Xingpu 邢浦 (near Shaoxing), they defeated a government army and killed General Xie Yan. The Jin dynasty, therefore, increased its military strength, and Liu Laozhi forced the rebels to retreat again over the sea at the end of the year. In 401, Sun En landed once more, took the fortress of Hudu 滬瀆壘 (today's Shanghai) and killed Yuan Shansong 袁山松 (d. 401), the Household Administrator (neishi 內史) of the Prince of Wu 吳. In the summer, the rebels landed in Dantu 丹徒 (close to Zhenjiang 鎮江, Jiangsu) and threatened to attack the capital. They destroyed Yuzhou 郁州 (near Lianyungang 連雲港, Jiangsu) and Guangling 廣陵 and captured General Gao Yazhi 高雅之 (d. 404). The first Jin general to defeat them was Liu Yu 劉裕 (363-422; the eventual founder of the Liu-Song dynasty 劉宋, 420-479) in Shanyin 山陰. Over the winter, the rebels retreated to the island, but returned in spring 402. The Jin armies under Xin Jing 辛景, the governor (taishou 太守) of the commandery of Linhai 臨海, defeated them immediately, killing the majority of the rebel troops. In despair, Sun En drowned himself in the sea. However, the rebellious movement continued for several years, partially under the leadership of Lu Xun, the brother-in-law of Sun En, and Xu Daofu 徐道覆. Sun's followers believed that he had become a water fairy (shuixian 水仙) and delivered offerings to his soul, including human sacrifice.

One outcome of Sun En's rebellion was a diminishment of the influence exerted by the eminent families over the military. The most crucial military units engaged in the rebellion, the Northern Headquarters Army, were composed of troops from lower origins (hanmen 寒門), who were also capable of ascending to officer positions. This is particularly evident in the personnel employed by Liu Yu, many of whom came from lower social backgrounds. The rebellion also highlighted the weakness of the Jin government in Jiankang and their reliance on powerful military leaders like Liu Yu, who consistently rose in honours and ultimately brought an end to the Jin dynasty.

The bibliographical chapter Jingji zhi 經籍志 of the official dynastic history Suishu 隋書 lists the collected writings Sun En ji 孫恩集, with a length of 5 juan. They are long lost.