however, the overall vietnamese military performance was not as successful as định's guerrilla activities. on june 5, 1862, định broke with the nguyễn army after the court's plenipotentiary phan thanh giản and another official, lam duy hiep, signed the treaty of saigon. this agreement ceded the three southern provinces of gia định, định tường and biên hòa to france; they became the colony of cochinchina. the treaty was accompanied by financial payments to france, religious concessions to missionaries and commercial opportunities for european merchants. militarily, the withdrawal of the nguyễn army deprived the resistance of the logistical support that could be provided by a regular force. it also permitted the french to concentrate their efforts against a single antagonist. politically, the treaty provided, for those vietnamese who needed one, a legal basis to collaborate with the french on cochinchinese soil. as a result, the colonial forces found it easier to recruit militia and administrative personnel among vietnamese who had been too afraid or too embarrassed to serve the french openly before the 1862 treaty. định then allied himself with võ duy dương to form the movement of popular self defense ("phong trao nhan dan tu ve"), creating an operations base in đồng tháp.