 He served as Dr. Sun Yat-Sen's personal bodyguard and was appointed as a battalion commander of the newly created 4th Corps of the National Revolutionary Army.In 1923 he joined the campaign to dislodge warlord Chen Jiongming from power and was promoted to regiment, brigade and ten division commander.During the Northern Expedition he led the 4th Corps and defeated Wu Peifu's warlord armies in central China.