Throughout most of this period of time, there were conflicts with the Japanese. The Japanese declared war on Germany early in World War I and had a large contingent in Versailles to participate in treaty negotiations. The resulting Treaty of Versailles in 1919 awarded Germany's holdings in the Pacific, North of the equator, including Shandong, China, to Japan. This led to outrage among the Chinese and to the May Fourth Movement protesting imperialism and instigating violence against westerners. The 1920s was an ongoing period of instability and warlordism. Both Sun Yat-sen and Yuan Shikai died. Chiang Kai-shek consolidated power through the Northern Expedition against warlords in 1926 to 1928, but never really controlled all of China. The Nanking Incident in 1927 again demonstrated Chinese hostility toward imperialist powers. The Chinese Communist Revolution was underway in the late 1920s, and the Japanese invaded Manchuria in 1931. Both of these hostilities continued, and Japan declared all out war on China in 1937. The Chinese Nationalist government was relocated to Chungking in Szechwan Province, and many students and faculty evacuated from Eastern Universities were relocated to Chengdu, where Graham was from 1932 to 1948. Chengdu itself was bombed by the Japanese as early as 1938. Meanwhile, the Soviet Union was engaged in military action in Xinjiang. Around 1942, Japan had taken over IndoChina and Burma, completely cutting off western China, except for flights over the Himalayas.