After the September 18 Incident of 1931, calls for resistance against Japan grew. Feng Yuxiang and Ji Hongchang, along with Wu Chengfang of the Communist Party, worked to form the Anti-Japanese Allied Army in Zhangjiakou. Ji, influenced by the Communists, joined the Party and became a leader of the Allied Army. The movement gained broad support, but Chiang Kai-shek and the Japanese launched a campaign against them. Despite the challenges, Ji Hongchang continued his efforts to resist Japanese aggression and save the nation.