3. This aroused animosity in Corralat, the prince of Mindanao; for if that district were to be converted, he would be greatly hindered in his piratical raids. He began to harass the village of Cagayan, so that the inhabitants could not go out freely to till their fields and care for their crops. Consequently, the province of San Nicolas established father Fray Pedro de San Agustin [22] as missionary in that district. He was a person born for military undertakings. His native place was the city of Valladolid and he was the son of Portuguese parents. He had studied philosophy and theology at Salamanca, but his inclination led him to read books of military deeds, in which his taste found a particular pleasure; and he became very expert in architecture, gunnery, and a great part of what is taught in military practice. He made use of these qualifications and talents by establishing and erecting the fort of Linao in the province of Caraga, an advanced outpost among the heathen and Moros. Its structure was well tested, for it resisted many assaults. He excellently instructed the Indians whom he converted, in this natural method of defense, and its utility has been proved in its always having been preserved. Then this father went, after the new election, to Cagayan. That district had before been tributary to Corralat, and the latter keenly resented its change of religion from that of its prince; therefore, he was always harassing them with wars and hostilities, in order to recover his power over them. As soon as father Fray Agustin assumed that charge, he exercised his skill in fortifying the village. He surrounded it with a stout stockade, well proportioned in its outlines, defending its curtains by communications of bulwarks. In the middle he raised another small redoubt, as a place of retreat in case of a sudden invasion. He disciplined the natives in the management of arms, and inspired them with courage, so that they should not turn coward in time of danger, or be intimidated by a multitude, which could not overcome them if they were thoroughly accustomed to firearms. In fact, they resisted excellently the surprises attempted by Corralat, who attacked them often with many men, and obliged him to retire with heavy loss.