the northern expedition was a guomindang movement against whom in china
Northern Expedition The Northern Expedition was a military campaign launched by the National Revolutionary Army of the Kuomintang (KMT), also known as the Nationalists, against the Beiyang government and other regional warlords in 1926. The purpose of the campaign was to reunify China, and the expedition was divided into two phases. The first phase was interrupted by the political split in the Kuomintang following the formation of the Nanjing faction in April 1927 against the existing faction in Wuhan.[5] The split was partially motivated by the purge of the Communists within the party, which marked the end of the First United Front, and Chiang Kai-shek briefly stepped down as the commander of the National Revolutionary Army.[6]
Second Sino-Japanese War Initially the Japanese scored major victories, capturing both Shanghai and the Chinese capital of Nanking in 1937. After failing to stop the Japanese in the Battle of Wuhan, the Chinese central government was relocated to Chongqing (Chungking) in the Chinese interior. By 1939, after Chinese victories in Changsha and Guangxi, and with Japan's lines of communications stretched deep into the Chinese interior, the war reached a stalemate. The Japanese were also unable to defeat the Chinese communist forces in Shaanxi, which waged a campaign of sabotage and guerrilla warfare against the invaders. While Japan ruled the large cities, they lacked sufficient manpower to control China's vast countryside. During this time, Chinese communist forces launched a counter offensive in Central China while Chinese nationalist forces launched a large scale winter offensive.