The Art of War played a large role in reshaping ancient China. The introduction of the text led eventually to the unification of China and the creation of history's most stable empire.  

The Art of War period: The Spring and Autumn era

Sun Tzu lived during the "Spring and Autumn" period of Chinese history. This was the golden age of ancient China, stretching from 722 BC to about 470 BC. (Click here for a timeline of important events in the period.) At the time, China was not a unified empire but a group of small states divided into dozens of principalities.  

During this period, a growing educated class gained influence in government and commerce because of its members' knowledge instead of their strength as fighters. The Chinese word shih, which originally meant a knight, came to mean a literate person during this era. Bureaucracy gained power as the feuding principalities consolidated under larger governments. As states began to tax individual landowners, peasants worked themselves free of their masters and practiced labor-intensive agriculture for a mostly vegetarian diet. Millet was supplemented by wheat from the north and rice from the south, and soybeans helped to revive the soil.

During this period, the most famous Chinese philosophers arose: Lao-Tzu, the author of the Tao Te Ching; Confucius; Motzi; and, though seldom recognized as such, Sun Tzu.  

The work that describes the history of the Spring and Autumn era is the Zuo Zhuan (commentary by Zuo on the Chun Qiu, the Chinese name for the era). Much of this work seems to be early writing, though some comments and prophecies may have been put in as late as the middle of the fourth century BC. This book describes events more fully and offers moral lessons and occasional comments, some by Confucius.

Enter Sun Tzu 

In 564 BC the eleven major states of China signed a nonaggression pact. During this period there was a balance of power among the major states of Chi, Chin, Tzin, and Chu. The smaller state of Chou was recognized as the ruler of the Chinese world and the historical imperial seat, but the emperor held no real power. After several hundred years of war, especially between Chu in the south and the large northern states, this pact gave the larger states a rest. The pact held for forty years. 

During this time, the larger states of China consolidated their power, eliminating dozens of smaller dukedoms. At the beginning of this period, there were about 150 principalities in China. By the end, there were only 40. Wars were also fought externally against the barbarians, expanding the territory of China.  

This peace between major states was broken in 506 BC by the kingdom of Wu, whose ruler was not a signatory to the pact. (Wu is on the map above, right below the mouth of the Yangtze River.) Note that this was only a few years after King Helu hired Sun Tzu as the head of his armies. The states of Wu and Yueh were upstart southern nations. The more civilized north considered them semibarbarian. At the time, the smaller northern state of Lu, the home of Confucius, had become the dominant state in China.  

Wu started by subjugating the southern state of Yueh and then going on to conquer the largest southern state, Chu. After this, Wu took the battle to the north. By 482 BC, twenty-seven years after the hiring of Sun Tzu, Wu had become the dominant state in China.  

After Sun Tzu's death, the power of Wu continued to grow, but it did not last. While Wu's armies were fighting in the north, the state of Yueh rose up and conquered the capital of Wu. This paved the way for the reemergence of the powerful Chu, which in a few more years had absorbed both Wu and Yueh into its boundaries.  

The Warring States Period

The rise and fall of Wu was followed by the Warring States period. During this period, the work of Sun Tzu grew in popularity, especially among the surviving successful states. Sun Tzu's descendant, Sun Ping of Chi, further popularized his work in the major states about 350 BC. In the Warring States period the total number of principalities was reduced to seven. In 221 the most powerful of these, Chin, established the empire that we call China. This empire has lasted until the present day, though its rulers have changed.