Rev. Dr. Charles Robert Hager was a Swiss-born American missionary sent to Hong Kong and China by the American Board of Commissioners for Foreign Missions (ABCFM) to start the Hong Kong Mission in 1883. He was best known as the baptizer of Dr. Sun Yat-sen, the first president and founding father of the Republic of China. Rev. Hager was the founder, and was regarded as the first Minister-in-charge, of the China Congregational Church in Hong Kong.

Sun Yat-sen, better known in China as Sūn Zhōngshān, was a Chinese revolutionary statesman, physician, and political philosopher who served as the first provisional president of the Republic of China and the first leader of the Kuomintang. He is called the "Father of the Nation" in the present-day Republic of China (Taiwan) and the "Forerunner of the Revolution" in the People's Republic of China for his instrumental role in the overthrowing of the Qing dynasty during the 1911 Revolution. Sun is unique among 20th-century Chinese leaders for being widely revered by both the Communist Party in Mainland China and the Kuomintang in Taiwan.