Little is known of Sun-tsu or master Su, author of the Taoist classic The Art of War. We do know he was a member of the landless aristocracy who had lost their lands during the early Spring and Autumn period.

Unlike other members of his class however, who eked out a living as wandering academics, Sun-tsu was a mercenary for the state of Wu during the 6th century BC and was thus a contemporary of Kung-fu-tsu.

According to tradition, King Helü of Wu hired Sun Tzu as a general in approximately 512 BC after finishing his military treatise, the Sun Tzu (named after the author, as was common in China prior to the Qin era). After his hiring, the kingdom of Wu, previously considered a semi-barbaric state, went on to become the most powerful state of the period by conquering Chu, one of the most powerful states in the Spring and Autumn Period. Sun Tzu, always wanting a peaceful and quiet life, suddenly disappeared when King Helu finally conquered Chu. Therefore his date of death remained unknown.
Quoted from Wikipedia.

Sun-tsu’s The Art of War has played a hugely important role in Taoist tradition in that it is considered to be the source of all later forms of martial art in China and has been very influential in determining the philosophy of strategy right up to the present day.

Mao Tse Tung was known to be an avid reader of Sun-tsu. Major Asian corporations examine The Art of War as compulsory study on a routine basis and the skill of competitors understanding and use of its advice is dreaded.

Military action is important to the nation — it is the ground of death and life, the path of survival and destruction, so it is imperative to examine it.
— Sun-tsu

Consider this:

I have heard of military operations that were clumsy but swift, but I have never seen one that was skillful and lasted a long time. It is never beneficial to a nation to have a military operation continue for a long time.

Food for thought in light of today’s Middle-Eastern conflicts.