The Art of War is an ancient Chinese military treatise that is attributed to Sun Tzu, a high ranking military general and strategist of the Kingdom of Wu who was active in the late-sixth century BC, during the late Spring and Autumn period. Composed of 13 chapters, each of which is devoted to one aspect of warfare, it is said to be the definitive work on military strategies and tactics of its time, and is still read for its military insights.
The Art of War is one of the oldest and most successful books on military strategy in the world. It has been the most famous and influential of China's Seven Military Classics: "for the last two thousand years it remained the most important military treatise in Asia, where even the common people knew it by name." It has had an influence on Eastern military thinking, business tactics, and beyond.
Sun Tzu emphasized the importance of positioning in military strategy, and that the decision to position an army must be based on both objective conditions in the physical environment and the subjective beliefs of other, competitive actors in that environment. He thought that strategy was not planning in the sense of working through an established list, but rather that it requires quick and appropriate responses to changing conditions. Planning works in a controlled environment, but in a changing environment, competing plans collide, creating unexpected situations.