Sun Yat-sen and Soviet envoy Adolph Joffe issued the Sun–Joffe Manifesto, which laid out a plan for Soviet aid to the Kuomintang (KMT) and cooperation with the Chinese Communist Party (CCP). This agreement helped turn earlier contacts into a concrete political and military partnership.
The KMT’s 1st National Congress in Guangzhou adopted policies supporting alliance with the Soviet Union and cooperation with the CCP, helping launch the First United Front. The “bloc within” approach meant CCP members worked inside the KMT while keeping their CCP membership.
The Whampoa Military Academy opened as a major training center for officers of the National Revolutionary Army (NRA). It became a key institution for building a unified, modernized force that could challenge regional warlords during the coming Northern Expedition.
Sun Yat-sen died in Beijing, removing the one leader whose prestige had helped keep the KMT–CCP alliance together. After his death, internal rivalry in the KMT grew sharper, especially between left and right factions and over how to manage cooperation with communists.
The Zhongshan (Chungshan) Warship Incident triggered a major political struggle inside the United Front coalition. It strengthened Chiang Kai-shek’s position within the KMT and helped him tighten control over military forces as preparations for a national campaign accelerated.
Chiang Kai-shek’s acceptance ceremony as commander-in-chief marked the formal start of the Northern Expedition, the NRA’s campaign to defeat warlord governments and unify China. At first, the advance benefited from United Front cooperation, Soviet advisers, and political organizing alongside military operations.
As the expedition moved up the Yangtze region, a Nationalist government based in Wuhan emerged under left-KMT leadership. This created a competing center of power and made KMT–CCP tensions harder to manage during a campaign that required unity.
During the NRA’s capture of Nanjing, violence against foreigners led to evacuations and naval bombardment by foreign warships. The incident increased international scrutiny of the Northern Expedition and added pressure on Nationalist leaders to control troops and local unrest.
Chiang Kai-shek’s forces and allied groups carried out mass arrests and killings of communists and leftists in Shanghai. The purge split the KMT and effectively ended the First United Front, turning the earlier alliance into open confrontation.
Communist-led forces launched an uprising in Nanchang after the breakdown of the United Front. Although it failed to hold the city, the event became a major starting point for the CCP’s shift toward organized armed struggle against Nationalist власти.
After internal political crises and shifting alliances, Chiang Kai-shek officially relaunched the expedition to push north against remaining Beiyang-aligned forces. The renewed campaign aimed to finish the military unification effort, even as the KMT–CCP split widened into civil conflict.
In Jinan, clashes between NRA troops and the Imperial Japanese Army turned into a major incident with heavy casualties and a Japanese occupation that continued for months. The confrontation showed that unification efforts were now tangled with foreign military power, especially in North China.
A bomb attack near Shenyang assassinated warlord Zhang Zuolin, a key leader of the Fengtian clique. His death weakened the Beijing-based Beiyang political order and changed calculations in the northeast, where Japanese influence was strong.
Zhang Xueliang announced that Manchuria would replace Beiyang symbols with the Nationalist flag, recognizing the Nationalist government’s authority. This step is widely treated as the political endpoint of the Northern Expedition, completing a nominal national unification under the Nanjing-based regime.
First United Front and the Northern Expedition (1923–1928)