In the early Northern Song Dynasty, in order to meet the needs of border defense, civil and military officials were strongly encouraged to study the military affairs and expeditions of past dynasties, and organized the compilation of China's first new military book, "The General Essentials of Military Classics". The book includes two parts: military theory and military technology, and has high academic value. Later, seven military books including "Sun Tzu" were compiled into "Seven Books of Martial Arts", which became a required course in martial arts.
