In the middle of the Spring and Autumn Period (770 BC-476 BC)， the states of the Central Plains thought of themselves as the central powers of the land and regarded the people of Wu as barbarians. They failed to appreciate that development in the State of Wu meant that they were rapidly catching up with， and even surpassing， the sophistication and power of the central states. Bronze smelting techniques advanced greatly among the Wu and made them the dominant metalworkers in all the lands. Metalworking skill meant improved swords and improved swords equated to greater military power. The State of Wu advanced rapidly and the beautiful gardens still in evidence in Suzhou today attest to the growing cultural sophistication that went hand in hand with the military development of the state.
In Huqiu， one of Suzhou’s noted beauty spots today， there is a place named Sword Pond (Chinese： Jian Chi)， where He Lü， the king， is said to be buried. Of the numerous and precious funerary objects found there， the most valuable were 3，000 fine swords. Qin Shihuang (259 BC-210 BC)， the first emperor of Chinese feudal times， after he had unified the territory of China， ordered his men to make swords just like these but they did not have the craftsmanship and skill of the Wu metalworkers and could not do it.
The prosperity and vitality of the vibrant Wu State proved the perfect environment for a young man full of enthusiasm and ambition—he was Sun Tzu. Sun settled down near Qionglong Mountain not far from the Wu capital and led a quiet， reclusive life. He made no effort at first to seek official position in the Wu administration
Qionglong Mountain， 340 meters high， is the highest peak in the Suzhou area. Hence the other name by which it is known， “FirstPeak of Wuzhong.” Local legend records that it was in a modest hut in the valley of Qionglong Mountain， that Sun Tzu first lived in the State of Wu. Today， a memorial archway， on which is written four Chinese characters， “兵法圣地” ( Bing Fa Sheng Di， meaning “Holy land of Military Tactics”)， stands at the gate to this hut， today known as Sun Wu Yuan. According to eminent local scholars， it was in this modest dwelling that one of the masterpieces of the ancient world， The Art of War， was produced.
Qionglong Mountain is located at the very centre of the most strategically important area of Wu territory. It is the tallest peak in the region and thus its commanding views were of the utmost military importance. With lush forests， rolling， expansive valleys abounding in clean flowing rivers， and an agreeable climate， the mountain overlooking Lake Taihu offered then， and indeed still offers today， a most attractive environment to live in.
According to the prestigious Chinese historical chronicle， the Spring and Autumn of Wu and Yue， at that time Sun Tzu withdrew completely from the world. His neighbours all regarded him as an eccentric， whose behavior was puzzling and unconventional. They certainly had not the slightest inkling that here was a man blessed with a genius that would shock the whole world. Living in his little hut， Sun immersed himself in writing his book and simultaneously he kept a close eye on the changing winds of political fortune， carefully calculating the optimum time to emerge and to make his mark in the world of political affairs.
The Wu king， He Lü， had long nurtured ambitions to carry out a military expedition northwards in order to expand the territory and power of the Wu State. But his first priority was to confront the strong， military power， which was the State of Chu. Chu， a state with a lineage stretching back almost one thousand years’， was an aggressive， expansionist power. It had， during the Spring and Autumn Period (770 BC-476 BC)， conquered as many as 45 states， expanding its territory one hundred times over. The Chu were a quintessentially martial and warlike people. It’s said that the people of Chu would feel they were shaming their ancestors if they didn’t conduct a major military expedition at least every three years and a major war at least every five years.
Why would the State of Wu even countenance attacking such a powerful western neighbour？ It seems the main reason lies in a longstanding oppression that the Wu suffered at the hands of the Chu and perhaps more importantly the fact that King He Lü was determined to pursue an aggressively， expansionist military policy.
Thus it came to pass that the State of Wu， in the eastern lands of China， began to inexorably build up and expand its military capabilities under the leadership of an ambitious king， who recognized from the very beginning that dreams of martial glory would remain just dreams for the State of Wu unless the mighty Chu could first be dealt with and defeated. However， the means by which such a seemingly all powerful force could be militarily defeated by what appeared an inferior power was a conundrum that greatly troubled King He Lü’s thoughts.