Sun Zi (孫子 in pinyin: Sun1 Zi3), known as Sun Tzu to western scholars, was the author of The Art of War (an influential ancient Chinese book on the use of the military). He is also one of the earliest realists in political science.
The only surviving source on the life of Sun Tzu is the biography written on the 2nd century BC by the historian Ssu-ma Ch'ien, who describes him as a general who lived in the state of Wu on the 6th century BC. However, the biography is not consistent with other sources about the period, and both the form and content of the book indicate that it was most likely written between 400 BC and 320 BC.
See also: Famous military writers