Sun Tzu's Art of War is the earliest book on the art of War in China and the earliest military work in the world. It predates Clausewitz's On War by about 2,300 years and is regarded as the "holy Canon of military science". There are about 6,000 words in all, thirteen of them. The author is Sun Wu, a general of the State of Wu, whose ancestral home was Le 'an of the State of Qi during the Spring and Autumn Period.