The state of Qin was located on the western frontier, and in the early years of the Warring States period, power was held tightly by the royal clan and noble families. These nobles ignored the interests of the state, using their privileges only to benefit themselves, leading to a situation where Qin was plagued by "political chaos, a weak military, and a lowly ruler," with its national power in steady decline. The other feudal states looked down on Qin, treating it as a barbarian tribe. In 361 BC, Duke Xiao of Qin ascended the throne at just 21 years old. Full of youthful vigor and determined to strengthen his state, he aspired to achieve great deeds, vowing to make Qin prosperous and powerful and to elevate its status among the feudal lords. Thus, he posted a notice seeking talented individuals, declaring, "Whoever can devise an extraordinary plan to strengthen Qin, I will grant him high office and share the land with him."
After hearing the news in the state of Wei, Shang Yang traveled from Wei to Qin. Shang Yang was a descendant of the ruler of the state of Wei, originally surnamed Gongsun, and was called Gongsun Yang. Because he was from the state of Wei, he was also known as Wei Yang. After arriving in Qin and implementing reforms that earned him merit, he was rewarded by Duke Xiao of Qin and enfeoffed in the land of "Shang," which is why he came to be called "Shang Yang" or "Lord Shang." From a young age, Shang Yang was fond of the study of law and governance, specializing in ruling through legal methods. After completing his studies, he went to the powerful state of Wei, hoping to display his great talents. The Wei prime minister, Gongshu Cuo, greatly appreciated him and made him his retainer. Not long after, Gongshu Cuo fell gravely ill and, during his illness, recommended to King Hui of Wei that Shang Yang succeed him as prime minister. Sensing that King Hui would not employ Shang Yang, he advised the king to kill him to prevent him from being used by other states. King Hui of Wei did not take Shang Yang seriously at all; after Gongshu Cuo died, he ultimately did not employ Shang Yang, nor did he kill him.
After arriving in the State of Qin, Shang Yang was introduced by Jing Jian, a favored minister of Duke Xiao of Qin, and met with the duke three times, presenting the strategies of the Way of Emperors, the Way of Kings, and the Way of Hegemons. Ultimately, he won over Duke Xiao with the Way of Hegemons. Then, Shang Yang proposed policies such as abolishing the well-field system, emphasizing agriculture and sericulture, rewarding military merit, standardizing weights and measures, and implementing the system of prefectures and counties, persuading Duke Xiao to carry out reforms to strengthen the state.
Duke Xiao of Qin greatly admired Shang Yang's strategies and appointed him as Zuo Shuzhang (a high-ranking official) to oversee the reforms. As Shang Yang was assisting Duke Xiao in planning the reforms, old aristocratic representatives such as Gan Long and Du Zhi, who were senior ministers, voiced opposition. They argued that the laws of the ancestors should not be changed, but Shang Yang countered with the principle of "establishing laws according to the times and creating rites based on circumstances." In the end, Duke Xiao supported Shang Yang's reforms.
Before issuing the reform decrees, Shang Yang worried that the people might not trust him, rendering the reforms mere empty words. To gain their trust, he set up a three-foot-tall wooden pole outside the southern gate of the capital's market and posted a notice stating that anyone who moved this pole to the northern gate would be rewarded with ten gold pieces. A crowd gathered, pointing and discussing, but no one dared to move it, uncertain if it was real. Shang Yang then raised the reward to fifty gold pieces. At that, a man mustered his courage, carried the pole straight to the northern gate, and Shang Yang immediately ordered the fifty gold pieces to be given to him. This event caused a great stir among the people, convincing them that the authorities kept their word. Following this, Shang Yang issued the reform decrees, which were quickly implemented throughout the state.
Shang Yang's reforms primarily included: abolishing the well-field system and opening up field boundaries; emphasizing agriculture while suppressing commerce, and rewarding farming and weaving; standardizing weights and measures; rewarding military merit and implementing a system of noble titles based on military achievements; organizing the populace into groups of five and ten households; abolishing the hereditary system of official positions and salaries, encouraging the nobility to earn merit through military service; reforming the household registration system and implementing collective punishment; and promoting the county system.
During the reform, the crown prince violated the law, and Shang Yang lawfully punished the prince's tutor, Gongzi Qian, and his teacher, Gongsun Jia. Later, when Gongzi Qian broke the law again, Shang Yang had his nose cut off as punishment. Seeing that Shang Yang enforced the law impartially, not even sparing the powerful and noble, the people were greatly shocked, and the entire state strictly implemented the new laws.
After the new laws had been implemented for several years, the people of the Qin state had ample supplies at home and in the streets, no one picked up lost items on the roads, there were no bandits in the mountains, the military became powerful, and the national strength grew day by day, causing the feudal lords to fear Qin. Duke Xiao of Qin promoted Shang Yang to the position of Grand Councillor. Through Shang Yang's reforms, Qin achieved great order and began to surpass the six eastern states, developing into the most prosperous and powerful feudal state in the late Warring States period.
In 342 BCE, the Zhou king and various feudal lords sent envoys to congratulate Qin on its growing power. In 340 BCE, taking advantage of Wei's defeat at the Battle of Maling, Qin allied with Zhao to attack Wei. Wei's Prince Ang led his army to meet the enemy but was outwitted by Shang Yang's stratagem and defeated, forcing Wei to cede the Hexi region (present-day eastern Shaanxi) and sue for peace with Qin. It was only then that King Hui of Wei regretted not heeding Gongshu Cuo's earlier advice. For his reforms and military achievements, Duke Xiao of Qin granted Shang Yang a fief of fifteen towns in the Shang region. However, Shang Yang's new laws were excessively harsh; he instituted collective punishment, added brutal penalties such as mutilation, rib extraction, and boiling in a cauldron. His system of granting noble ranks based on military merit undermined the interests of the aristocracy, and his strict enforcement of the law bred deep resentment among Qin's noble families during his tenure as the chief reformer.
In 338 BC, Duke Xiao of Qin died, and his son Prince Si succeeded him, becoming King Hui of Qin. At this time, old nobles like Gongzi Qian, seeking revenge for past grievances, began to counterattack. They falsely accused Shang Yang of plotting rebellion and urged King Hui to arrest him. Upon hearing the news, Shang Yang fled in haste, reaching the border where he tried to stay at an inn. The innkeeper demanded identification, refusing to lodge him otherwise, because Shang Yang's own law stipulated that no one could harbor a person without proper credentials, with violators facing collective punishment—a classic case of being hoist by his own petard. Left with no choice, Shang Yang fled to the State of Wei, but since he had helped Qin defeat Wei through trickery, Wei harbored a grudge and refused to take him in. Shang Yang then returned to his fiefdom of Shang in Qin, where he organized his followers into an army to attack the State of Zheng, hoping to atone for his crimes through military merit. Qin dispatched troops to suppress him, and Shang Yang was defeated and killed at Mianchi in Zheng. King Hui of Qin had his body brought back to the Qin capital, where it was subjected to the punishment of dismemberment by chariots, and Shang Yang's entire clan was exterminated.