 In 1829 , Duyet suffered another blow when Nguyen Van <unk> , an ally whom he appointed to run Cambodia for him died . The general nominated another subordinate to replace his colleague Nguyen Van Xuan , but Minh Mạng overruled him and instead appointed one of his mandarins Bui Minh Duc to the post . Although the emperor formally asked Duc to cooperate with Duyet , Minh Mạng then appointed Duc to the post of Minister of the Board of War , putting him above the general in the chain of command , effectively making Duyet irrelevant with regards to the running of the protectorate . In 1831 , just before Duyet 's death , Minh Mạng began to dismantle his military infrastructure and sending his component units to other parts of Vietnam , and sent a loyalist General Nguyen Van Khue to Gia Định , allowing him to dilute the viceroy 's power . In addition , no government reports could be officially approved and sent to the capital until it was countersigned by civil officials sent south by the emperor . These moves against southern autonomy gradually increased the resentment and regionalist sentiments among the local population . 
