勤王運動
While the French were trying to establish control over Cambodia, a large scale Vietnamese insurgency – the Cần Vương movement – started to take shape, aiming to expel the French and install the boy emperor Hàm Nghi as the leader of an independent Vietnam. The insurgents, led by Phan Đình Phùng, Phan Chu Trinh, Phan Bội Châu, Trần Quý Cáp and Huỳnh Thúc Kháng, targeted Vietnamese Christians as there were very few French soldiers to overcome, which led to a massacre of around 40,000 Christians. The rebellion was eventually brought down by a French military intervention, in addition to its lack of unity in the movement.