How A New Pope Is Chosen
The Cardinals who gather to elect the next Pope will follow a 1996 document issued by Blessed John Paul II, as amended by Pope Benedict XVI in 2007 and 2013, which outlines the process to be followed if the papacy, or Apostolic See, is vacant.
Pope Benedict XVI made clear his intention to resign at a Consistory of Cardinals on February 11, 2013. The resignation took effect on February 28, 2013 at 8 PM Vatican City time (2 PM EST). At that time, the papacy was vacant (sede vacante) and the procedure for calling a conclave to elect a new pope commenced.
First Steps
The Camerlengo (or chamberlain), currently Cardinal Tarcisio Bertone, administers the property and finances of the Church while there is a sede vacante.
Next, the papal apartment is sealed.
Third, the Dean of the College of Cardinals, currently Cardinal Angelo Sodano, informs the world community, telling world leaders, diplomatic corps and the other cardinals of the vacancy.
Fourth, the heads of the offices of the Roman Curia cease to exercise their offices with few exceptions, one being the Major Penitentiary, currently Cardinal Manuel Monteiro de Castro, and the Camerlengo.
Fifth, all Cardinals under 80 years old travel to Rome; Cardinals over 80 may choose to do so and attend the preparatory sessions and general congregations before the conclave. However, they are not permitted to take part in the election.
Finally, the Cardinals meet daily in General Congregations between the resignation and the start of the election. They plan for the election; oversee the destruction of the Fisherman's ring (used to seal papal documents) ensuring that there are no forgeries; and choose two theologians known for sound doctrine to present meditations on (1) issues facing the Church and (2) the need for careful discernment in choosing the Pope.
The Papal Election
The preparation for the conclave began immediately after the resignation took effect.
Second, at the beginning of the conclave itself, the order "extra omnes" (all out) is given and everyone not authorized to be present must leave.
Secrecy and avoiding outside influence is vital. The Cardinals take two oaths of secrecy, one when they arrive in Rome and one when the conclave begins. The Sistine Chapel is swept for electronic listening devices; the Cardinals are barred from outside communications, including reading the news; and they must stay together at the Domus Santa Marta, a residence on Vatican grounds.
Fourth, the few people allowed near the Cardinals must take an oath of secrecy: aides/masters of ceremonies; housekeeping and cooking staff; two doctors; and priests for hearing confessions. A Cardinal who is ill and requires assistance may have a personal aide.
Fifth, election is by secret ballot, and a two-thirds vote of the Cardinals present is required to elect a Pope. Cardinals wear red "choir" dress while voting.
Sixth, each Cardinal writes the name of his chosen candidate on a ballot that is then folded in half. He carries the completed ballot in the air so all can see it, places it on a paten (plate) placed on the altar and drops the ballot into a repository.
Seventh, two votes are held each morning and each afternoon until a Pope is elected. Depending on when the conclave begins and how long it takes for all of the Cardinals to take their oaths, a single vote may be held the first day.
Eighth, if the vote is inconclusive, the ballots are burned in such a way that black smoke will be seen coming from the Sistine Chapel’s chimney by those gathered in St. Peter’s Square (traditionally, the black smoke was caused by using wet straw; now chemicals are used). If a vote is successful, white smoke rises.
Finally, if there is an impasse after three days, the Cardinals take a short break for prayer, informal discussion among themselves and a brief spiritual exhortation by the Senior Cardinal Deacon, currently Cardinal Jean-Louis Tauran, and then go through up to three more series of seven votes, break, etc. If there is a deadlock, the Cardinals are to have a day of prayer and dialogue. After that, the two Cardinals with the most votes on the last balloting are the only candidates for election and they are prohibited from voting. The number required for a valid vote remains two-thirds.
After A New Pontiff is Chosen
First, the Dean of the College of Cardinals asks the newly chosen pontiff, "Do you accept your canonical election as Supreme Pontiff?" If the answer is yes, he immediately becomes the Bishop of Rome and Pope. He also chooses the name he wishes to use at this moment. (The first time a Pope chose a new name for himself was in the sixth century; it became the norm 1,000 years ago.)
Second, the newly elected Pope changes from the red choir dress into white papal vestments and returns to the Sistine Chapel where the Cardinals offer a sign of obedience and homage.
Third, the new Pope goes to the balcony over the main door of St. Peter's Basilica. The Senior Cardinal-Deacon announces in Latin "habemus papam" (we have a Pope) and gives his baptismal name, surname and chosen papal name.
Fourth, the new Pope gives his urbi et orbi (to the city and world) blessing.
Finally, he is formally installed during an inauguration Mass within a few days.
Brief Background on Conclaves
Conclave comes from the Latin words for "with a key," cum clave. The Cardinals are locked "with a key" in the Sistine Chapel to elect a new Pope.
In 1059, Nicholas II gave Cardinals the leading role in electing Popes, to fight off feuding and lobbying by families and civil officials.
In 1179, the Third Lateran Council restricted the election to Cardinals and decided it would take a vote of two-thirds of the Cardinals to elect the Pope.
In 1268, following the death of Clement IV, it took three years to choose the next Pope, Gregory X. That happened only after local officials (in Viterbo, Italy where the election was) locked the Cardinals in a building with no roof and threatened they would only get bread and water. Gregory X was elected almost immediately.
Gregory X then stipulated the Cardinals should gather in the town where the Pope died and be locked in without a key to avoid outside influence. The Cardinals couldn't receive any funds during the conclave from the papal treasury and, after eight days, would be fed bread and water.
In 1274, conclave rules were spelled out at the Council of Lyons. Many of these rules remain.
(From an article by Msgr. Charles Antonicelli, a priest of the Archdiocese of Washington. He has a law degree from The Catholic University of America, and a licentiate in sacred theology from the Pontifical University of St. Thomas Aquinas in Rome.)