Xi Jian 郗鑒 (269-339), courtesy name Daowei 道微, was a high minister and calligrapher of the Eastern Jin period 東晉 (317-420). He hailed from Jinxiang 金鄉 in the commandery of Gaoping 高平 (today in Shandong) and assembled his own local body of troops during the disturbances of the Rebellion of the Eight Princes. He was a secretary (yuan 掾) in the staff of Prince Sima Lun 司馬倫 (249-301), and was then promoted to the position of court gentleman in the Imperial Secretariat (zhongshu shilang 中書侍郎).
When Emperor Yuan 晉元帝 (r. 317-322) re-founded the Jin dynasty, he made Xi Jian first General of rousing dragons (longxiang jiangjun 龍驤將軍), then regional inspector (cishi 刺史) of the province of Yanzhou 兗州. During the reign of Emperor Ming 晉明帝 (r. 322-325), he participated as General appeasing the west (anxi jiangjun 安西將軍) in the suppression of Wang Dun's 王敦 (266-324) rebellion. In this function, he had the command over the troops of the provinces of Yangzhou 揚州 and Jiangxi 江西, and resided in Hefei 合肥 (today in Anhui).
Together with Wang Dao 王導 (276-339) and Yu Liang 庾亮 (289-340), Xi Jian supported the enthronement of Emperor Cheng 晉成帝 (r. 325-342). He was therefore given the military title of General-in-chief of chariots and cavalry (cheji da jiangjun 車騎大將軍) and the civilian title of Cavalier attendant-in-ordinary (sanji changshi 散騎常侍), and was made regional inspector of Xuzhou 徐州.
Xi Jian's participation in the suppression of the rebellion of Su Jun 蘇峻 (d. 328) and Zu Yue 祖約 (d. 330) under the command of Tao Kan 陶侃 (259-334) and Wen Jiao 溫嶠 (288-329) yielded him the honorific title of Minister of Works (sikong 司空), then that of Defender-in-chief (taiwei 太尉). Xi Jian was also granted a title of nobility, namely Commandery Duke of Nanchang 南昌郡公. His posthumous title is Duke Wencheng 文成公 "The Cultured-Accomplished".
Xi Jian was a famous calligrapher. The "spirit and breath" of his grass script (caoshu 草書) was clear and elegant (qixi qingya 氣息清雅). Dou Ji 竇臮 (early 8th cent), author of the rhapsody Shushu fu 述書賦, praised his style as "floating and emerging in deep structures" (hou shi fu chen 厚實浮沉), like the rocking sides of a fisherman's boat move up and down. Zhang Huaihuan's 張懷瓘 (early 8th cent.) critical book Shuduan 書斷 calls his style "unsurpassed in merging antiquity with vigour" (gu er qie jing 古而且勁).
The book Xuanhe shupu 宣和書譜 from the Song period 宋 (960-1279) adds that his style was brief and unadorned (lüe wu liu zhi 略無留滯), but full of richness, beauty and spirit (fengmao hongli 豐茂宏麗, bu fa fengshen 不乏風神).
Short fragments of Xi's masterpieces are preserved on the model collections Lanling tie 蘭陵貼 and Chunhuage tie 淳化閣法貼.