 The French government was attempting to impose a protectorate in Tonkin (northern Vietnam) at this period, in the face of bitter opposition from Liu Yongfu's Black Flag Army.The Black Flag Army was covertly armed and supplied by China, and the role of the new naval division was to cut the flow of weapons and ammunition to the Black Flags by blockading the Gulf of Tonkin.The Tonkin Coasts naval division included the ironclads "Bayard" and "Atalante" from Courbet's Mediterranean command and the cruiser "Châteaurenault" from Algiers.