In the third year of his reign [512 B.C.] Ho Lu, king of Wu, took the field with Tzŭ-hsu [i.e. Wu Yuan] and Po P’ei, and attacked Ch’u. He captured the town of Shu and slew the two prince’s sons who had formerly been generals of Wu. He was then meditating a descent on Ying [the capital]; but the general Sun Wu said: "The army is exhausted. It is not yet possible. We must wait"…. [After further successful fighting,] "in the ninth year [506 B.C.], King Ho Lu addressed Wu Tzŭ-hsu and Sun Wu, saying: "Formerly, you declared that it was not yet possible for us to enter Ying. Is the time ripe now?" The two men replied: "Ch’u’s general Tzŭ-ch’ang, [4] is grasping and covetous, and the princes of T’ang and Ts’ai both have a grudge against him. If Your Majesty has resolved to make a grand attack, you must win over T’ang and Ts’ai, and then you may succeed." Ho Lu followed this advice, [beat Ch’u in five pitched battles and marched into Ying.] [5] This is the latest date at which anything is recorded of Sun Wu. He does not appear to have survived his patron, who died from the effects of a wound in 496. In another chapter there occurs this passage:[6] From this time onward, a number of famous soldiers arose, one after the other: Kao-fan, [7] who was employed by the Chin State; Wang-tzu, [8] in the service of Ch’i; and Sun Wu, in the service of Wu. These men developed and threw light upon the principles of war. It is obvious enough that Ssu-ma Ch’ien at least had no doubt about the reality of Sun Wu as an historical personage; and with one exception, to be noticed presently, he is by far the most important authority on the period in question. It will not be necessary, therefore, to say much of such a work as the _Wu Yüeh Ch’un Ch’iu_, which is supposed to have been written by Chao Yeh of the 1st century A.D. The attribution is somewhat doubtful; but even if it were otherwise, his account would be of little value, based as it is on the _Shih Chi_ and expanded with romantic details. The story of Sun Tzŭ will be found, for what it is worth, in chapter 2. The only new points in it worth noting are: (1) Sun Tzŭ was first recommended to Ho Lu by Wu Tzŭ-hsu. (2) He is called a native of Wu. (3) He had previously lived a retired life, and his contemporaries were unaware of his ability. The following passage occurs in the Huai-nan Tzŭ: "When sovereign and ministers show perversity of mind, it is impossible even for a Sun Tzŭ to encounter the foe." Assuming that this work is genuine (and hitherto no doubt has been cast upon it), we have here the earliest direct reference for Sun Tzŭ, for Huai-nan Tzŭ died in 122 B.C., many years before the _Shih Chi_ was given to the world. Liu Hsiang (80-9 B.C.) says: "The reason why Sun Tzŭ at the head of 30,000 men beat Ch’u with 200,000 is that the latter were undisciplined."