Catholicism was propagated in Mamburao and the town was placed under the third convent district based in Cavite. Mamburao was subjected to attack by the Mindanao Moro, guided by its former Mamburao inhabitants who wanted to claim their lands and have a prosperous life there between the 17th and 18th centuries. Mamburao, supported by its population, was even made into a sea haven by the Moros, who used it as base of their sea attacks against Friar induced settlements on coastal towns in Mindoro, Luzon and Visayas.