Sun Bin (died 316 BC) and Pang Juan (died 342 BC) were Chinese generals and military strategists who lived during the Warring States period of Chinese history.
They were both tutored in military strategy by the hermit Guiguzi and developed a close friendship, while studying in seclusion with their teacher in mountainous regions. Pang left and ventured to the Wei state and impressed the king with his proposals on policies to strengthen the Wei state. Later he led the Wei armies to victories in battles against smaller states and became a highly respected figure in Wei.
Pang invited Sun Bin to join him in serving the Wei state later but he was actually secretly jealous of Sun because Sun learnt more from their teacher than him. Pang Juan framed Sun Bin on charges of treason. The King Hui. was furious and ordered Sun Bin to be condemned to face-tattooing (criminal branding) and had his kneecaps removed. Pang pretended to take pity on Sun and tried to trick him to compile his knowledge about military strategy into a book and kill him later. Sun Bin discovered Pang’s true intentions and feigned madness. Sun escaped from Wei with the help of officials from the Qi state and became an important strategist and statesman in Qi later.
A struggle between Pang Juan and Sun Bin began, as each of them led his respective state’s armies to attack the other. At the Battle of Maling, Sun used a strategy to lure Pang Juan’s army to follow the Qi army by feigning defeat. Pang was eager to defeat Sun Bin and he led a light cavalry unit in pursuit, but fell into an ambush by the Qi army in a narrow valley. The Wei army suffered a crushing defeat and the Wei crown prince was captured by Qi forces, while Pang Juan committed suicide.