The Tongmenghui was a secret society and underground resistance movement founded by Sun Yat-sen, Song Jiaoren, and others in Tokyo, Empire of Japan, on 20 August 1905, with the goal of overthrowing China's Qing dynasty. It was formed from the merger of multiple late-Qing dynasty Chinese revolutionary groups.

Sun Yat-sen successfully united the Revive China Society, Huaxinghui and Guangfuhui in the summer of 1905, thereby establishing the unified Tongmenghui (United League) in August 1905 in Tokyo. While it started in Tokyo, it had loose organizations distributed across and outside the country. Sun Yat-sen was the leader of this unified group. Other revolutionaries who worked with the Tongmenghui include Wang Jingwei and Hu Hanmin. When the Tongmenhui was established, more than 90% of the Tongmenhui members were between 17 and 26 years of age. Some of the work in the era includes manhua publications such as the Journal of Current Pictorial.