Zhang Dingfan belonged to the circle of General Bai Zongxi 白崇禧. While the 1911 Revolution overthrew the Qing Empire, it did not unify China which was ruled by regional warlords. The central national government was in the south, home of Sun Yat-Sen. It did not have the military strength to defeat all of the warlords, especially those in the North. The regional forces were constantly shifting allegiances or fighting each other. Bai was from Central China which included Jiangxi, Zhang's home province. Bai eventually joined with Chiang Kai-shek who became head of the Nationalist Government. It was an uneasy alliance of convenience. Nevertheless, Bai's armies were critical in the success of Chiang's two Northern Expeditions forming the left and center of the advances. Zhang was a field general they both depended upon and was rewarded to be the Mayor of Shanghai while remaining in command of the 13th Army in the heart of China.
After the success of his Northern Expeditions which gave him control of the governments of the northern provinces, Chiang Kai-shek proceeded to "Cleanse the Nationalist Party" 清党. Communist members infiltrated the Nationalist party over the years. They also maintained a military power base as well as local headquarters in all major cities. Chiang understood a ruthless campaign to root them out. Bai had friends amongst them. Zhang helped one of them escape from Shanghai and resigned shortly afterwards in 1929.
There were many instances of commanders who helped their friends when the politics changed. Even the most powerful among them overlooked this during the internecine warfare. The attitude was different concerning the war with Japan. When that war began in ernest, Chiang Kai-shek recalled Zhang to the Military Affairs Commission and promoted him as well.
Xhang died in 1945.[1]