Born in Shandong Province in eastern China, Wu received a traditional Chinese education. He joined the Baoding Military Academy in Beijing and embarked on a career as a professional soldier. Wu joined Yuan Shih kai's new Beiyang Army but after Yuan's death in 1916, the army split into hostile factions. Wu's Zhili forces were sabotaged by one of his chief allies Feng Yu-xiang. Later Wu sided with the Kuomintang and was made Commander-in-Chief of the Imperial Chinese Army with the rank of Field Marshal, the only living Chinese general to bear such a rank.