Sun Tzu proved on the battlefield that his theories were effective (for example, at the Battle of Boju), that he had a successful military career, and that he wrote "The Art of War" based on his tested expertise. However, the "Zuozhuan", a historical text written centuries earlier than the "Shiji", provides a much more detailed account of the Battle of Boju, but does not mention Sun Tzu at all. Beginning around the 12th century, some scholars began to doubt the historical existence of Sun Tzu, primarily on the grounds that he is not mentioned in the historical classic "Zuo zhuan", which mentions
Sun Tzu again the concubines giggled. Sun Tzu then ordered the execution of the king's two favored concubines, to the king's protests. He explained that if the general's soldiers understood their commands but did not obey, it was the fault of the officers. Sun Tzu also said that, once a general was appointed, it was his duty to carry out his mission, even if the king protested. After both concubines were killed, new officers were chosen to replace them. Afterwards, both companies, now well aware of the costs of further frivolity, performed their maneuvers flawlessly. Sima Qian claimed that Sun Tzu later