護國戰爭
In December 1915, Yuan Shikai declared himself Emperor of a new Empire of China. This was opposed by almost all the generals and officers in the Beiyang Army, with many of the Southern Provinces once again rebelling against the imperial government, beginning the National Protection War. By March 1916, the situation forced Yuan to abdicate and he died not long after. This implosion of the Beiyang government's centralized authority led to the beginning of the Warlord Era, during which the Beiyang Army fragmented into a number of regional military cliques that began to vie for control of the country.