尊室說
On May 19, 1883, Henri Rivière and his French expeditionary force left Hanoi for Black Flags’ camps. Black Flags’ scouts noticed them and informed Liu Yongfu. A fatal attack waged by Black Flags wounded Rivière heavily and he died. Rivière’s head was displayed outside the west gate of Hanoi the next morning. On May 27, Paris government sent a telegram to the governor of Cochinchina, “France shall revenge her brave children.” Alexandre-Eugène Bouët, who was in Cochinchina during this time, was appointed as military commander in Tonkin. On August 16, 1883, Bouët took Hải Dương and forced Black Flags to retreat to Paper Bridge (Cầu Giấy). But the terrible weather precluded further operations, so Bouët went back to Hanoi and asked France for more troops. At the same time, Jules Harmand, together with Anatole-Amédée-Prosper Courbet, moved to south to force Huế court to accept French protection in Tonkin and Annam. Emperor Hiệp Hòa was forced to negotiate. On September 25, 1883, imperial officials Trần Đình Túc and Nguyễn Trọng Hợp signed the Harmand Treaty. Huế court could still govern central Vietnam without interference from France except in matters of customs. Tôn Thất Thuyết and Nguyễn Văn Tường executed Emperor Hiệp Hòa, showing their opposition. Meanwhile, Hoàng Kế Viêm was instructed to secretly close his ranks with Chinese in Sơn Tây.