Auxiliary bishops frequently represent the residential or diocesan bishop in a specific area of the diocese. In most parts of the world the size of a diocese, its population concentrations, the demands of administration and the specialized character of an apostolate will require a diocesan bishop to select from among his priests certain persons whose abilities and experience suggest them as episcopal collaborators in the work of the Church. In turn, the residential bishop will depend upon the auxiliary bishop for advice in important decisions and matters of major importance. They become his "first assistants."

The faithful most likely become familiar with the auxiliary bishop through his parish visitations, celebrations of the sacraments, especially confirmation, and other liturgical and church celebrations. An interesting note in the Directory for the Pastoral Ministry of Bishops speaking about the assignment of duties to an auxiliary bishop says "When requesting an auxiliary, the diocesan Bishop should present a detailed description of the offices and tasks which he intends to entrust to the auxiliary, even when it is a case of replacing an auxiliary bishop who has been transferred elsewhere or who has resigned his office. In this way the diocesan bishop personally avails himself of the opportunity to evaluate the quality of his episcopal service for the good of the whole diocese. The diocesan bishop should not entrust the auxiliary bishop with the care of a parish nor with tasks of a purely marginal or occasional nature."

As their biographies indicate, each of the new auxiliary bishops has been assigned a titular see. These are extinct dioceses where the Church once enjoyed great presence and vitality. Various factors, such as shifting population and persecutions contributed to a decrease and even elimination of the Catholic faith. In order to preserve the memory of these sees and their people alive, the custom arose of assigning these titles to bishops who were assisting other bishops or who were serving in various offices of the Roman Curia. Both of the new bishops' titular sees are in North Africa, the present day territory of Algeria.