91 years ago today, on March 19, 1934 (February 5, 1934 in the lunar calendar), Chiang Kai-shek borrowed the four-horse coalition to remove Sun Dianying's army. On March 19, 1934, Sun Dianying's entire army collapsed, the situation was over, and the Ningxia War, which lasted for several months, ended. In the summer of 1933, Chiang Kai-shek appointed Sun Dianying as the reclamation supervisor of the western district of Qinghai, and ordered him to lead the 41st army to Qinghai, and then intercepted Ma Hongkui halfway through. Ma Hongkui and Ma Hongbin were unable to block their own strength, and Shang and Qinghai Ma Bufang and Ma Buqing refused to unite with Sun. The four-horse coalition had about 50,000 people, and Sun Dianying had about 70,000 troops. From December 1933, the two sides fought fiercely outside Dengkou, Shizui, Pingluo and Ningxia, and they won and lost each other. In late January 1934, Sun Jun's two divisions attacked the northwestern suburbs of Ningxia, and encountered strong resistance from the four-horse alliance. In February, Sun Jun launched a siege battle and attacked Ningxia City at night, but failed. Later that month, Sun Jun attacked Ningxia for the second time, forming a stalemate. At this time, Chiang Kai-shek put pressure on Sun, stopped issuing 41 military salaries, abolished the Qinghai West District Tunnel Reclamation Office, and removed Sun Dianying from all his posts, which greatly affected Sun Jun's combat effectiveness. On the night of March 19, Sun Jun all retreated, more than 6,000 prisoners, and more than 20,000 of the army were recruited by Yan Xishan. After the battle, Ma Bufang was appointed commander of the newly formed Second Army by Chiang Kai-shek, and Ma Buqing was appointed commander of the 5th Cavalry Division.