護国戦争
On 12 December 1915 Yuan, supported by his son Yuan Keding, declared himself emperor of a new Empire of China. This sent shock waves throughout China, causing widespread rebellion in numerous provinces. On 25 December former Yunnan governor Cai E, former Jiangxi governor Li Liejun () and Yunnan Gen. Tang Jiyao formed the National Protection Army () and declared Yunnan independent. Thus began the National Protection War ().