In 1972 some bamboo texts in a Han period tomb were excavated in Yinqueshan 銀雀山, Shandong, among them the Sunzi bingfa and Sun Bin bingfa. This proves that at the beginning of the Han period there was a tradition of a Master Sun from Wu (the Sunzi bingfa), and one from a Master Sun from the state of Qi (the Sun Bin bingfa). The text of the Yinqueshan Sunzi is somewhat differing from the received version, but identical to quotations in Han and Tang period sources. The tomb library also contained wooden slips (mudu 木牘) inscribed with chapters titles of the Sunzi, with six chapters of a first part (shangbian 上編), and seven chapters, the so-called Qishi 七勢 "Seven conditions", as second part (xiabian 下編). There are also five full chapters which are not found in the received version of the Sunzi.
The Sunzi stresses that warfare is essential for the survival of a state, and is therefore a field which is necessarily to be paid attention to. Once defeated in war a country will never rise again. The enlightened ruler therefore has to care for war, and good generals study it in detail and have to be prepared in advance.