On May 4, 1919, young students in Beijing held a large-scale demonstration to protest against the imperialist countries' support for Japan's aggression against China at the Paris Peace Conference. This eventually developed into a nationwide patriotic movement against imperialism and feudalism. The "May Fourth" Movement demonstrated the strong will of the Chinese people to protect national independence and fight for democratic freedom, marking the beginning of China's New Democratic Revolution. In 1949, the State Council officially announced May 4 as China's Youth Day.
On November 11, 1918, World War I, which lasted for four years, ended with the victory of the Allied powers including Britain, the United States, and France, and the defeat of the Central Powers including Germany and Austria. In January 1919, the victorious Allied powers convened a peace conference in the Palace of Versailles, Paris. The Republic of China, as a victorious country, participated in the conference. The representatives of the Republic of China proposed reasonable demands such as abolishing foreign privileges in China and canceling the Twenty-One Demands, but these were all rejected. The conference even decided that Japan would take over all the privileges that Germany had in China. In response to this treaty that undermined national sovereignty, the representatives of the Republic of China were ready to sign it. When the news spread, the whole country was enraged and the public was furious. The May Fourth patriotic movement, led by students, began like a volcanic eruption.
In the afternoon of May 4, more than 3,000 students in Beijing gathered in Tiananmen Square and marched, shouting slogans such as "Return Our Qingdao, Strive for Sovereignty Externally, Eliminate Traitors Internally." They called on people from all walks of life to take action, oppose the aggressive acts of imperialism, and safeguard China's territory and sovereignty. This movement received support and solidarity from workers and people of all social strata. Workers in cities such as Shanghai and Nanjing launched strikes or demonstrations. Under the pressure of the entire nation, the Beiyang government was forced to release the arrested students, dismiss officials such as Cao Rulin, and instructed the representatives attending the conference in Paris to refuse to sign the peace treaty.