Why did the May 4 movement occur in 1919?

The May 4 Movement in 1919 emerged as a response to China's dissatisfaction with the Treaty of Versailles, which transferred German concessions in China to Japan instead of returning them to Chinese sovereignty. This sparked widespread nationalist sentiment among students and intellectuals, who protested against foreign Imperialism and the weakness of the Chinese government. The movement emphasized modernization, reform, and a call for cultural and political change, laying the groundwork for future political developments in China.