Shang Yang, also known as Wei Yang and originally surnamed Gongsun, was a statesman, chancellor and reformer of the State of Qin. Born in the Zhou vassal state of Wey during the Warring States period, he took up office in the Qin state, where his policies laid the administrative, political and economic foundations that would eventually enable Qin to conquer the other six rival states, unifying China into a centralized rule for the first time in history under the Qin dynasty. Scholars consider it likely that both he and his followers contributed to The Book of Lord Shang, a foundational philosophical work for the school of Chinese legalism.

Qin was an ancient Chinese state during the Zhou dynasty. It is traditionally dated to 897 BC. The Qin state originated from a reconquest of western lands that had previously been lost to the Xirong. Its location at the western edge of Chinese civilisation allowed for expansion and development that was not available to its rivals in the North China Plain.