Sun Bin (孫臏) (died 316 BC) was a military strategist who lived during the Warring States Period in ancient China. Born in Qi, he was a member of the Sun family, a family famed for producing military strategists. He is considered a descendant of Sun Tzu, and may have helped edit the Art of War. He also wrote his own military treatise, the Sun Bin Bing Fa, that was recently rediscovered after being lost for almost 2000 years.
Sun Bin later escaped to Qi. His military skills were recognized, and he came to serve under King Wei. He formed a strong partnership with the military commander Tian Ji. They defeated the state of Wei (not to be confused with King Wei) at the Battle of Guiling against forces led by Pang Juan. When Tian Ji was banished from Qi due to court politics, Sun Bin followed him into exile to Chu. After King Wei died, the new king of Qi, King Xuan, recalled Tian Ji and Sun Bin. Sun Bin and Tian Ji later defeated Wei again at the Battle of Maling.
Although ancient texts mention that the original Sun Bin Bing Fa contained 89 chapters, the rediscovered copy contains only sixteen verifiable chapters. Since the tomb also contained fragments of the Art of War, some chapters might actually be lost chapters from the Art of War instead.
The newly discovered text provides historians with a different perspective on the Battle of Guiling and the Battle of Maling. In addition, the Sun Bin Bing Fa shows one major strategic divergence from the Art of War; while Sun Tzu advised against siege warfare, the Sun Bin Bing Fa contains numerous stratagems for assaulting a sieged city. This paralleled a shift in strategic consideration of siege warfare during the later stages of the Warring States Period.