1. 曹操 Ts‘ao Ts‘ao or 曹公 Ts‘ao Kung, afterwards known as 魏武帝 Wei Wu Ti [A.D. 155–220]. There is hardly any room for doubt that the earliest commentary on Sun Tzŭ actually came from the pen of this extraordinary man, whose biography in the _San Kuo Chih_[94] reads like a romance. One of the greatest military geniuses that the world has seen, and Napoleonic in the scale of his operations, he was especially famed for the marvellous rapidity of his marches, which has found expression in the line 說曹操曹操就到 “Talk of Ts‘ao Ts‘ao, and Ts‘ao Ts‘ao will appear.” Ou-yang Hsiu says of him that he was a great captain who “measured his strength against Tung Cho, Lü Pu and the two Yüan, father and son, and vanquished them all; whereupon he divided the Empire of Han with Wu and Shu, and made himself king. It is recorded that whenever a council of war was held by Wei on the eve of a far-reaching campaign, he had all his calculations ready; those generals who made use of them did not lose one battle in ten; those who ran counter to them in any particular saw their armies incontinently beaten and put to flight.”[95] Ts‘ao Kung’s notes on Sun Tzŭ, models of austere brevity, are so thoroughly characteristic of the stern commander known to history, that it is hard indeed to conceive of them as the work of a mere _littérateur_. Sometimes, indeed, owing to extreme compression, they are scarcely intelligible and stand no less in need of a commentary than the text itself.[96] As we have seen, Ts‘ao Kung is the reputed author of the 新書, a book on war in 100,000 odd words, now lost, but mentioned in the 魏志.[97] 2. 孟氏 Mêng Shih. The commentary which has come down to us under this name is comparatively meagre, and nothing about the author is known. Even his personal name has not been recorded. Chi T‘ien-pao’s edition places him after Chia Lin, and 鼂公武 Ch‘ao Kung-wu also assigns him to the T‘ang dynasty,[98] but this is obviously a mistake, as his work is mentioned in the 隋書經籍志. In Sun Hsing-yen’s preface, he appears as Mêng Shih of the Liang dynasty [502–557]. Others would identify him with 孟康 Mêng K‘ang of the 3rd century. In the 宋史藝文志,[99] he is named last of the 五家 “Five Commentators,” the others being Wei Wu Ti, Tu Mu, Ch‘ên Hao and Chia Lin. 3. 李筌 Li Ch‘üan of the 8th century was a well-known writer on military tactics. His 太白陰經 has been in constant use down to the present day. The 通志 mentions 閫外春秋 (lives of famous generals from the Chou to the T‘ang dynasty) as written by him.[100] He is also generally supposed to be the real author of the popular Taoist tract, the 陰符經. According to Ch‘ao Kung-wu and the _T‘ien-i-ko_ catalogue,[101] he followed the 太乙遁甲 text of Sun Tzŭ, which differs considerably from those now extant. His notes are mostly short and to the point, and he frequently illustrates his remarks by anecdotes from Chinese history.