After the Northern Expedition ended in 1928, Yan Xishan, Feng Yuxiang, Li Zongren and Zhang Fakui broke off relations with Chiang shortly after a demilitarization conference in 1929, and together they formed an anti-Chiang coalition to openly challenge the legitimacy of the Nanjing government.

[11] Compared to other senior party officials like Hu Hanmin and Wang Jingwei, the political status of Chiang Kai-shek in the Kuomintang (KMT) was lower in the beginning.

Chiang began his rise to prominence in 1917 during the Constitutional Protection Movement and the formation of the Guangzhou government, where he displayed his military talent.

In the course of the expedition, Chiang had managed to form an alliance with warlord armies of Feng Yuxiang, Yan Xishan and Li Zongren.

While Chiang emerged as the paramount leader of the Republic of China, the reunification soon ran into issues as different factions in the Kuomintang disagreed over demilitarization at a military conference in 1929.

His partial control of Shandong provided him with large amounts of revenue needed for his military; however this was greatly affected by the fact that there was a famine and rebellion in Gansu.

Chiang did not tolerate this action and prepared for war, while Feng was bribed with offers of large amounts of territory in Shandong for his neutrality.

[22] Following the demilitarization conference in 1929, Li Zongren, Bai Chongxi and Huang Shaohong of the Guangxi clique broke off relations with Chiang in March 1929, which effectively started the confrontation between these commanders and the Nanjing government.

Later in the same month, Yan assumed the leadership position in the anti-Chiang coalition, with the assistance of Feng and Li while Zhang Xueliang chose to remain "loyal" to Chiang.

Feng Yuxiang would lead the Northwest Army and march from Henan to Shandong, attacking Xuzhou while also applying pressure on Wuhan.

In response to the preparations, the Nationalists assigned Han Fuqu to set up defense in the southern bank of the Yellow River to counter the Shanxi Army.

[25] On 11 May, the Central Army led by Chiang Kai-shek launched a series of general offensives against Yan Xishan and Feng Yuxiang.

While the Nationalist government in Nanjing came out victorious, the conflict was financially costly which had a negative influence on the subsequent Encirclement Campaigns over the Chinese Communist Party.

After the entrance of the Northeast Army into central China, the defense of Manchuria was significantly weakened, which indirectly led to Japanese aggression in the Mukden Incident.