Mambog is the boundary between the towns of Malolos and Bulacan. A river served as territorial boundary among the other barrios of the town except Taal which is adjacent by land. The barrio was established in 1868. the name Mambog was derived from a Spanish missionary El de Mambon Santos de Roque. But according to other reliable sources the name Mambog came from a name of a tree that grows in the barrio called Mambog. It is a big tree with wide branches and leaves. The patron saint of the barrio is San Roque which they enshrined at their chapel so that they will able to live together and seek his intersession especially in times of sickness. They consider their saint as performing miracles. According to an old story, an old man came to the barrio begging for alms, but he wanted branches of the tree Kakawati to be used for the repair of a chapel he did not mentioned especially the pews. This strange incident continued to haunt them because they were not able to give the old man what he wanted. But one day as they enter their chapel, they found out that some of the pews are broken. So it came to their mind that their chapel is the one the old man is referring to, and the beggar is San Roque himself. Their devotion to San Roque is founded that their belief that he is a miraculous man and able to heal the sick so they conducted novenas in his honor specially on his feast day on August 16. The life of San Roque is really miraculous according on an ancient history in France, in a certain town, was hit by an epidemic San Roque treated the sick causing him to be contaminated. So he fled to the mountain and their in the company of a dog, he was treated and healed. The barrio is composed then as of this writing of 263 families 1429 people. They earn their living by means of farming and for women, sewing clothes. In their peaceful lives their religious life continued to advance. Their chapel is the place where they meet and their religious activities are centered.
2,748 as of 2007 Source: NSO Census of Population, 2007