The People's Party (Khana Ratsadon) stages a bloodless coup, transforming Siam from an absolute to a constitutional monarchy.
A conference chaired by Nguyễn Ái Quốc (Hồ Chí Minh) in Hong Kong merges Vietnamese communist groups into the Communist Party of Vietnam.
Vietnamese colonial soldiers organised by the VNQDĐ mutiny at Yên Bái; the revolt fails and Nguyễn Thái Học is executed.
Nguyễn Thái Học and others found the Vietnamese Nationalist Party (VNQDĐ) in Hanoi, seeking independence through armed struggle.
Caodaism, a syncretic religion, is formally founded in Cochinchina, with its Holy See at Tây Ninh.
Reformist Phan Châu Trinh dies in Saigon; his funeral becomes a nationwide patriotic demonstration.
Nationalist leader Phan Bội Châu dies in Huế after years under French house arrest.