勤王運動
Leader of the rebel guards Trinh Van Can was the son of an impoverished rural labourer from mountainous Vinh-Yen province. Can joined the "Garde Indigene" (native gendarmerie) as a youth and served his entire adult life on the remote Tonkinese frontier guarding prisoners and fighting bandits for the French. According to historian Tran Huy Lieu, Can's rebellious tendencies were shaped by his admiration of De Tham, having failed to track down De Tham's bandit gang in the mountainous and forestry terrain in Tonkin. Can's father had reportedly participated in the Cần Vương movement in the 1880s. Can reportedly contemplated an uprising for years. He spotted the opportunity when the French had grown preoccupied with the war in Europe.