Q. 1. What is a Cardinal Bishop?
A. 1. Cardinal Bishops are members of the highest order within the College of Cardinals. From among their number they elect the Dean of the College, who, with the confirmation of the Pontiff, presides over its meetings.
The title Cardinal Bishop contains a two-fold historical reference. In the first place cardinal is a title given to a principal adviser to the Bishop of Rome. Its use appears to date from about the fourth century (300s). With time it came to be applied to the incumbents in certain major ecclesiastical offices associated with the See of Rome. Since 1059, those appointed cardinals have been the exclusive electors of the Bishop of Rome. However, while their title still identifies cardinals by these ancient offices (deaneries, churches, dioceses), cardinals no longer have a formal role in their governance. They are today almost always bishops of dioceses or curial officials, not priests or deacons of Rome, and as cardinals they are papal electors and advisors.
The title bishop is a reference to one of the suburban dioceses (called the suburbicarian sees) which make up the Roman ecclesiastical province. The bishops of these dioceses (the number has varied through history) appear to have played a role since the fourth century in consecrating and installing the Pope. In doing this they were presided over by one of their number, the Bishop of Ostia.
Today the actual bishops of the seven suburbicarian sees have no role in the election of the Pope. Instead, six Cardinal Bishops hold the title of those sees, with the Dean of the College of Cardinals holding the title of two sees, the See of Ostia and the See to which he had title prior to his election as Dean. In addition to these Cardinal Bishops, certain Patriarchs of Eastern Churches hold the rank of Cardinal Bishop.