The Zhao Feiyan waizhuan 趙飛燕外傳 "Outer (inofficial) biography of Zhao Feiyan", also called Zhao Hou zhuan 趙后傳 "The story of Empress Zhao", Zhao Hou biezhuan 趙后別傳 "An alternative biography of Empress Zhao", or Feiyan waizhuan 飛燕外傳 "Outer story of Feiyan", is a short story about the life of Empress Zhao Feiyan 趙飛燕, consort of Emperor Cheng 漢成帝 (r. 33-7 BCE) of the Han dynasty 漢 (206 BCE-220 CE), and her sister. The book is attributed to a certain Ling Xuan 伶玄 (during the Qing period 清, 1644-1911, called Ling Yuan 伶元 in order to avoid the surname of the Kangxi Emperor 康熙, r. 1662-1722, Xuanye 玄燁). Ling Xuan was related to Fan Yi 樊嫕, who was a lady-in-waiting in the palace. His courtesy name was Ling Ziyu 伶子于 and he came from Lushui 潞水 (modern Changzhi 長治, Shanxi). The version in the collection Gushi wenfang xiaoshuo 顧氏文房小說 includes a preface by the author where it is said that he was a contemporarian of the philosopher Yang Xiong 揚雄 and was advisor (xiang 相) to the Prince of Huainan 淮南 and later commandant (duwei 都尉) of the commandery of Hedong 河東. The book is first listed in Song period 宋 (960-1279) bibliographies like in Chen Zhenxun's 陳振孫 Zhizhai shulu jieti 直齋書錄解題, for which reason it must be assumed that is was surely not compiled by a Han period person, but it was never openly called a forgery because it was quoted in Sima Guang's 司馬光 universal history Zizhi tongjian 資治通鑒 that had a canonical status. The Republican expert for early novellas Lu Xun 魯迅 analysed the language of the text and was convinced that it was a product of the Tang period 唐 (618-907), yet the modern scholar Hou Zhongyi 侯忠義 explained that Han period stories were not fashionable during that time, and sees the Zhao Feiyan waizhuan as an Eastern Jin period 東晉 (317-420) text.
The twin-sisters Zhao Yizhu 趙宜主 and Zhao Hede 趙合德 came from the princedom of Jiangdu 江都, where their father Feng Wanjin 馮萬金, served as a retainer of the prince. The family name of Zhao was given to them because it was that of the wife of the mayor of their home-town Gusu 姑蘇 (modern Suzhou 蘇州, Jiangsu). Yizhu was called Feiyan "flying swallow" because of her graceful appearance. When their father died the two sisters made their life by singing and dancing in the capital and so attracted the attention of some courtiers who managed to have them enter in the imperial harem, where both soon became favourites of the emperor. Zhao Feiyan was even made empress. The book narrates a tragic story of intrigues, jealousy, illicit relationships, and love. The literary quality of this biography is relatively high. It also gives insight into the life in the imperial palace at the end of the Former Han period 前漢 (206 BCE-8 CE). This vivid mixture of real events and phantasy make the small book Zhao Feiyan waizhuan China's oldest novella, as the Ming period 明 (1368-1644) scholar Hu Yinglin 胡應麟 argues in his collection Shaoshi shanfang bicong 少室山房筆叢. The Song period writer Qin Chun 秦醇 compiled an enlarged version of it, the Zhao Feiyan biezhuan 趙飛燕別傳.
The book is included in the collectanea Gushi wenfang xiaoshuo, Shuofu 說郛, Han-Wei congshu 漢魏叢書, Lüchuang nüshi 綠窗女史, Wuchao xiaoshuo 五朝小說, Guang Han-Wei congshu 廣漢魏叢書, Longwei mishu 龍威秘書, Bao Hongye congshu 鮑紅葉叢書, Wuyishizhai congchao 無一是齋叢鈔, Han-Wei xiaoshuo caizhen 漢魏小說采珍 and Siku quanshu 四庫全書. It is also included in Wu Cengqi's 吳曾祺 collection Jiu xiaoshuo 舊小說 and Li Gefei's 李格非 Wenyan xiaoshuo 文言小說.
Li Shuihai 李水海 (ed. 1994). Zhongguo xiaoshuo da cidian 中國小說大辭典, Xian-Qin zhi Nanbeichao 先秦至南北朝, p. 248. Xi'an: Shaanxi renmin chubanshe.
Li Xueqin 李學勤, Lü Wenyu 呂文鬰 (1996). Siku da cidian 四庫大辭典, Changchun: Jilin daxue chubanshe, vol. 2, p. 2165.