The Christian bishop is one of the most original historical figures of the period of transition between the ancient and medieval world, in which the Greco-Roman and Judaeo-Christian cultural heritage converged. Between the 4th and 5th centuries, many people came to the episcopate who, because of their social status and intellectual formation, became the leaders of the society of the time. The sacred character implicit in their priestly status gave them a deep freedom of action and of speech before the powerful, an auctoritas and a prestige that reinforced their capacity for leadership. Twenty professors and researchers from different Spanish universities analyze the many facets represented by the figure of the bishop in late Roman society, giving life to a work that is an exponent of the advances experienced by studies on Late Antiquity and Christianity.