Cardinals are members of what is called the Sacred College, the "senators" of the Roman Catholic Church. They are the principal counselors of the pope.
Their influence on the continuity of the church is enormous, as it is both their privilege and duty to meet within 15 days of a pope's death and -- in a secret meeting in the Vatican's Sistine Chapel -- elect his successor.
While the color of their hat and robes is similar to that of the vividly red male bird of the same name, the bird took its name from the church title, not the other way round.
The title is derived from the Latin, cardo, meaning hinge, and goes back 600 years. Near the beginning of the 15th century, Pope Eugene IV said, "As the door of a house turns on its hinges, so on the cardinalate does the Apostolic See, the door of the whole church, rest and find support."
As recently as the 19th century, a cardinal did not have to be a priest, much less a bishop. Since 1983, the church's Code of Canon Law has not only required that cardinals be priests, but bishops as well.
And yet, a pope can make exceptions, and John Paul II did in the case of the elderly French Jesuit, the Rev. Henri de Lubac. Under church law, Father de Lubac needed to be consecrated a bishop before entering the College of Cardinals, but the priest insisted that this was bad theology.
So the pope created a dispensation and appointed the priest a cardinal anyway.
In some parts of the world, church leaders have urged dispensations for women as well. At the recent synod in Rome of cardinals, archbishops and bishops, there was stony silence in St. Peter's Basilica as Bishop Ernest Kombo from the Congo made his startling proposal, that "women should have access to the highest posts of the church hierarchy and they should be named cardinals."
It is not seen as possible -- at least not now.
Not all the living cardinals are permitted to take part in the election of a new pope. Since a decree of Paul VI, those over the age of 80 have been excluded.
Seventeen years could go by before that exclusion applies to Cardinal-designate William H. Keeler.
A shared duty of the archbishop of Baltimore after his investiture as one of the 30 new cardinals at the Vatican Nov. 26 was spelled out at a meeting of the college in June.
At that meeting, according to the Catholic magazine Commonweal, the 114 cardinals from 54 countries who were in attendance were told by the pope that he wanted "an extensive examination of conscience by the Catholic Church leading to an open confession of sins, errors and crimes committed in the church's name."
Pope John Paul has suggested that he wants the kind of apology that was made in the case of Galileo to be considered by the cardinals for the Bohemian reformer John Huss, who was burned at the stake by church authorities in 1415.
The pope has also called for reviews of the involvement by churchmen in the African slave trade and excesses of the Crusades in Morocco.
Pope John Paul already has publicly admitted "errors of the Inquisition" and church injustices toward Jews during an appearance in a Rome synagogue.
So while the duties of the College of Cardinals are largely administrative -- especially those in the Roman Curia -- the influence of heads of archdioceses such as Baltimore's, when honored with the ancient title of Cardinal, can be far-ranging.
John Krol, Philadelphia (retired)
John Carberry, St. Louis (retired)
Luis Aponte Martinez, San Juan, P.R.
William Baum, Vatican City (formerly of Washington, D.C.)
Joseph Bernardin, Chicago
Bernard Law, Boston
John O'Connor, New York
James Hickey, Washington
Edmund Szoka, Vatican City (formerly of Detroit)
Roger Mahony, Los Angeles
Anthony Bevilacqua, Philadelphia