Feng Guozhang
In December 1915 Yuan Shikai declared himself Emperor. This was opposed by almost all the generals and officers of the Beiyang Army, from Duan Qirui and Feng Guozhang on down. More importantly, many outlying provinces such as Yunnan openly opposed him. Yuan was forced to back down from his imperial designs. Both Duan and Feng refused to support him in power any further, and in the end the only prominent Beiyang general to remain loyal was the irrepressible Zhang Xun. Yuan died soon afterward. After his death the Beiyang Army split into cliques led by Yuan's principal protégés. Duan Qirui's Anhui clique and the Zhili clique, founded by Feng Guozhang but led after Feng's death by Cao Kun and Wu Peifu, were the principal Beiyang cliques. Disunited, the power of the Beiyang Army was challenged by provincial armies such as Yan Xishan's forces in Shanxi and Zhang Zuolin's Fengtian clique.