National Pacification Army founded by Zhang Zuolin
The National Pacification Army (NPA), also known as the Anguojun or Ankuochun (Chinese: 安國軍), was a warlord coalition led by Fengtian clique General Zhang Zuolin, and was the military arm of the Beiyang government of the Republic of China during its existence.
The army was formed in November 1926 after the Fengtian victory in the Anti-Fengtian War, the NPA was tasked with countering the advance of the Kuomintang (KMT)-aligned National Revolutionary Army (NRA) of Chiang Kai-shek, who had launched the Northern Expedition in June 1926.: 3  In addition to its Fengtian Army core, the NPA also included Zhili clique generals, such as Sun Chuanfang.: 18  The NPA suffered a series of serious military defeats inflicted by Chiang and his warlord allies, including Feng Yuxiang, Li Zongren and Yan Xishan. On the southern front, the NPA was pushed back from Jiangsu and Henan after fierce fighting against the Guominjun and the NRA. On the western front, they fought Shanxi forces under Yan Xishan. Following these setbacks, a conference of NPA leaders in June 1927 established a military government and proclaimed Zhang Zuolin as Generalissimo, whereupon all military and civilian power was placed in his hands.
Despite having achieved a few victories in mid-1927 in Jiangsu and extensive victories in Shanxi, the NPA could not defeat the Kuomintang forces and soon retreated north and east of Tianjin. Following Zhang Zuolin's assassination by the Japanese Kwantung Army in the Huanggutun Incident on 4 June 1928, he was succeeded by his son, Zhang Xueliang, who disbanded the National Pacification Army and swore allegiance to the Kuomintang government in Nanjing.