The Liutao 六韜 "Six Secret [Teachings]" is a military classic traditionally attributed to Taigong 太公 Jiang Shang 姜尚 (also known under the names Lü Shang 呂尚, Jiang Wang 姜望, Jiang Ziya 姜子牙), ancestor of the house of the state of Qi 齊, which is known for ist military expertise. From the language it can easily be seen that the book must be of a very later date. Another hint is the use of cavalry units (qibing 騎兵) which were unknown in the early Western Zhou period 西周 (11th cent.-770 BCE). The discussion of hegemony and some ritual usages shows that the compilation has taken place during the Warring States period 戰國 (5th cent.-221 BCE).
The title is derived from the titles of the six chapters. The book is structured as a discussion of question and answers between Taigong and rulers King Wen 周文王 and King Wu of Zhou 周武王 (ca. 1050 BCE).
The book was already quite widespread during the 4th century. It is mentioned in the Zhuangzi 莊子 as Liutao 六弢 and the imperial bibliography Yiwenzhi 藝文志 in the official dynastic history Hanshu 漢書, where 237 chapters written by Taigong are mentioned.
In 1972 bamboo slips from a Han period 漢 (206 BCE-220 CE) tomb library were unearthed in Yinqueshan 銀雀山 among which fragments of the Liutao was included. It might be that the Liutao was not written by a single author but originated from the hands of many persons over a long period of time. The content of the preserved chapters is largely identical to the received version. During the Song period 宋 (960-1279) it was included into the canon of the Seven Military Classics (Wujing qishu 武經七書). From that time on the Liutao consisted of 60 chapters. There are some fragments which can be extracted as quotations from the Liutao in other literature, especially encyclopedias from the Tang 唐 (618-907) and Song periods, like the Qunshu zhiyao 群書治要, as well as the preserved fragments of Yinqueshan and Dunhuang 敦煌.
The first two chapters, Wentao 文韜 and Wutao 武韜, deal mainly with political strategy and are based on Confucian, Daoist, legalist and strategist thinking. The four other chapters describe troop formations, equipment, command and tactics, personal abilites of troops and commanders, training, transmission of orders and messages, logistics, and special tactics depending on circumstances. Various types of warfare are described in detail, like siege war, war of defense and attack, pursuit of inimical troops, battle in mountains, in forest, in swamps, at night, chariot attack, cavalry and infantry attack, and the war with fire. All these practical tactics are described much more detailed than other military books like the Sunzi bingfa 孫子兵法, Wuzi 吳子 or Weiliaozi 尉繚子.
In some respects, the Liutao delivers details not known from other sources, such as the fact that each general disposed of a command chain (guhong yuyi 股肱羽翼) of 72 persons. It also mentions that an army had specialist troops among them to erect fortifications or to do other engineering work. The delivering of secret messages is also talked about, as well as of the strengths of each type of troop.
The author(s) of the Liutao make clear that warfare is only a means of securing the wealth of a people and that war should, as far as possible, avoided. It should be forbidden to burn fields or to destroy dwellings. Submitting enemies should be spared their lives. Similarly, a general has to display benevolence to his own troops and has to share with them all sufferings of the field. Troops during training should become accustomed to the field work of the peasants to be able to supply themselves. Military training was to be done in a kind of snowball effect, beginning with small groups which then were to train larger units, until the whole army was to learn how to move on the battlefield.
The Liutao was a very widespread and popular strategy book used by Zhuge Liang 諸葛亮, Sun Quan 孫權, and the Tang period general Li Jing 李靖. It is often quoted in Tang period encyclopedias, like the Tongdian 通典. From the Ming period 明 (1368-1644) on many scholars called the Liutao a forgery, a claim that was later somewhat softened by the Qing period 清 (1644-1911) scholar Tan Xian 譚獻 who stressed that although the Liutao is not a Western Zhou period book it was nevertheless one of the most important military classics. Sun Tongyuan 孫同元 and Wang Renjun 王仁俊 have collected fragments from the Liutao quotes in other books and so compiled the Liutao yiwen 六韜逸文 "Surviving quotations from the Six Secret Teachings". The Liutao is included in the collectanea Xu guyi congshu 續古逸叢書.
Sheng Dongling 盛冬鈴 (1992). "Liutao 六韜", in: Zhongguo da baike quanshu 中國大百科全書, Zhongguo lishi 中國歷史, vol. 2, p. 616-617. Beijing/Shanghai: Zhongguo da baike quanshu chubanshe.
Zhang Lie 张烈 (1989). "Liutao 六韜", in: Zhongguo da baike quanshu 中國大百科全書, Junshi 軍事, vol. 1, p. 716. Beijing/Shanghai: Zhongguo da baike quanshu chubanshe.
1.文韜 Wentao Civil secret teaching
2.武韜 Wutao Martial secret teaching (content rather political)
3.龍韜 Longtao Dragon secret teaching (military organisation)
4.虎韜 Hutao Tiger secret teaching (military equipment)
5.豹韜 Baotao Leopard secret teaching (tactical solutions)
6.犬韜 Quantao Canine secret teaching (component forces chariots, infantry, cavalry)