As China sank into chaos, with the KMT banished, Yuan's lieutenant Li Yuanhong revived the Republican Constitution and became president. Li reconvened the National Assembly, but anarchy ensued, and China was left without any central authority. Many of the major warlords that came to power had originally served as officers in Yuan’s Beiyang Amy. Other warlords came to power through their backing of provincial military interests or foreign powers, such as Japan.The warlords were not uninteresting, however. Feng Yuxiang, the "Christian warlord," baptized his troops before battle with a firehose and inspected their fingernails. Wu Peifu, known as the "Philosopher General," owned the world's largest diamond. Zhang Zuolin, the "Mukden Tiger," liked young boys, and had at least five wives. On August 24, 1917, when China declared war on Germany, warlords began to seize German assets in Qingdao, Tianjin, and Hankou. In 1917, Sun Yat-sen returned to China (in 1915, he had asked the Second International, a Communist organization in Paris, to help China establish the world's first socialist government). In 1921 he established a military government in Guangzhou (1921-1925) and later expanded into Wuhan (1925-1927). Sun began planning the Northern Expedition, a campaign to rid China of warlords and unite China.