Francisco de Vitoria, one of the key figures in the Theology of the sixteenth century, was the principal influence on those Spanish bishops who participated decisively in the Council of Trent and who contributed to the shaping of its canons De Reformatione with the principals of doctrine and discipline which would affect the life and office of bishops. As is well known, in his lectures given at the University of Salamanca, Francisco de Vitoria has left us a treasure of doctrinal riches, which would serve as a source to enrich all of those disciples of his, who afterwards would take their places as the great bishops and teachers of their times. From his commentaries to the Secunda-secundae of Saint Thomas, and from his Relectiones Theologicae on the Church, one can establish what would constitute his own thinking on the Church, and more to the point, on the office of bishop. One discovers in his lectures a dogmatic consideration on the bishop-Pastor which lays the basis of their concrete responsabilities (moral, ascetic and pastoral) in the dioceses where they govern, that is to say, their responsabilities to the souls given over to their pastoral care. Following the Angelic Doctor, who lays the basis of ecclesiastical power in Christ, the Head of the Church, Vitoria, in turn, derives the power of the bishop from that of Christ himself, and, as a result, he considers each bishop to be the Vicar of Christ in his Church and head of his own particular Church. Making use of another biblical image, Vitoria looks upon the bishops as the spouse of his Church, in imitation of Christ. He should care for it, as a husband should care for his wife who merits all of his attention and concern; he cannot abandon her, because between them there exists a binding force tamquam perpetuum which obligates him to remain faithful. From this doctrinal basis of the episcopal office Vitoria derives some practical demands which assure the faithlul carrying-out of the pastoral mission: the responsability to reside in the diocese, near his sheep; the responsability of trying to supply priest; the responsability of attempting to achieve through serious effort his own sanctification. A particular church will be a faithful reflection of what its bishop is. And the bishop responds to the holiness of his flock through two principal means: to see to it that in his diocese sound doctrine is preached, and to correct with fortitude; he should also come to know the faithful personally and attend to the material needs of those most in need, as befits a pater pauperum. The figure of the bishop which we can outline in Vitoria's theology does not appear as an ideal image, but rather as the true image of the bishop who is consequent with the ontological reality of his episcopal consecration and of his office: the responsability of the bishop in his diocese is born of the ontological reality which is given him by means of the Sacrament (the special identity with Christ as Head) and through the reception of the concrete office (a special relation to his particular Church and with its souls). The doctrine of Vitoria concerning the episcopal office constitutes an important milestone in the history of theology. The affirmation of the divine institution of the episcopal order led him to the conclusion which would later be declared by the Magistery of the Church at the end of the nineteenth century, and afterwards, by the second Vatican Council.