Sun Chuanfang
In the early morning hours of October 23, General Feng Yuxiang betrayed the Zhili clique by pulling off the Beijing Coup. He put President Cao under house arrest. Wu reacted furiously at this betrayal by pulling his army from the front to rescue Cao. Zhang pursued and attacked Wu's rear, defeating him at Tianjin. Wu escaped to the Central Plains where Sun Chuanfang held the line against Zhang.