Founding of the Chinese Communist Party
Also called: First National Congress of the CCP
In July 1921 thirteen delegates met in the French Concession of Shanghai and, with Comintern support, founded the Chinese Communist Party, choosing Chen Duxiu as its leader.

ScareCriterion12 · CC BY-SA 4.0 · Source
After the Russian Revolution and the May Fourth Movement, communist study groups formed in Beijing, Shanghai and elsewhere around Li Dazhao and Chen Duxiu, and the Comintern sent agents to help organize a party. The First National Congress opened on 23 July 1921 in a house in Shanghai’s French Concession; among the thirteen delegates, who represented some fifty members, was Mao Zedong from Hunan. When concession police raided the meeting, the final session moved to a boat on South Lake at Jiaxing in Zhejiang, and Chen Duxiu, who was not present, was chosen as leader.
Beginning as a small circle of intellectuals, the party grew by leading labour movements, and on the Comintern’s instructions formed the First United Front with the Nationalists in 1924.