(RNS) "In the church," Chicago Cardinal Francis George once said, "everything has happened at least once!" That's no surprise given that the Catholic Church is a nearly 2,000-year-old institution that has adapted to radically different epochs.
But electing a new pope while the former pope is still alive? That's rare.
Indeed, this colorful and curious history continues to be written in today's headlines, as George and 114 other cardinal electors gather in Rome to choose a successor to Benedict XVI -- the first pope to resign in six centuries, and after a troubled papacy that has many historians reaching back to the Renaissance for apt comparisons.
So what are some other firsts and lasts, quirks and facts of papal history that you should know about? There are plenty, and Religion News Service has compiled a handy guide:
-- Cardinals picking a pope in a conclave held in the Sistine Chapel is actually a (relatively) recent development. In the early centuries of the church, the pope -- who is the Bishop of Rome -- was elected in various ways, though usually by the clergy of the diocese, a choice that was then affirmed (or rejected) by the people.
-- In 236 A.D., a man named Fabian -- not even a candidate -- was acclaimed pope after a dove, the symbol of the Holy Spirit, landed on his shoulder.
-- For several centuries, the Roman aristocracy and secular rulers often controlled the process. The College of Cardinals wasn't given the principal right to elect the pope until 1059.
-- In 1179, the College of Cardinals was given the exclusive right to choose a new pope, and a two-thirds majority was set as the threshold for a winning vote (later changed to two-thirds plus one).
-- Until modern times, a pope could also be elected by a compromise among the cardinals or by "acclamation," which means that all of the cardinals would have to unanimously declare their support for a single candidate. Now a candidate must win a secret ballot, no matter how long it takes.
-- At times there have been as few as a dozen cardinals voting in a conclave. Pope Sixtus V (1585-1590) set the top number at 70, and that was not changed until the 20th century when the ceiling was gradually raised to 120, though John Paul II often surpassed that limit.
-- In 1970, Pope Paul VI ruled that cardinals who were more than 80 years old when a pope died could not take part in a conclave; there are a total of 207 living cardinals, but 90 of them are more than 80 and cannot vote. Two others have said they cannot take part, leaving 115 electors.
-- The longest interregnum between popes lasted two years and nine months, between 1268 and 1271. During that time, the cardinals meeting in Viterbo, a town outside Rome, could not agree on a candidate until they were forced to do so by the king of France and other rulers.
-- After the Viterbo debacle, Pope Gregory X in 1274 established what we know today as the conclave (Latin for "with a key"), in which the cardinals are essentially locked inside a room -- and in olden times deprived of meals -- until they settle on a successor.
-- In modern times, conclaves usually last less than a week, and often no more than a day or two. The last long conclave was in 1740 and lasted six months.
-- The last conclave held outside of Rome was in Venice, in 1800.
-- Ballots have been burned since the 1417 conclave, but the practice of using white smoke -- created by adding dry straw to the ballots, or, more recently, chemicals -- to signal the election of a pope was first recorded in 1914. Before that, church bells were rung and cannons fired to signal the election of a pope.
-- Technically, any baptized male can be elected pope, but the last time the cardinals reached outside their ranks was in 1378, when they chose Urban VI.
-- The last pope who was not a priest when elected was Leo X (1513-1521). He had to be ordained before taking office.
-- A pope must also be a bishop. The last cardinal elected pope who was not a bishop was Bartolomeo Cappellari, a monk who became Pope Gregory XVI in 1831. He was made a bishop four days after his election and then became pope.
-- The first pope to change his name: a fellow named Mercury, elected in 533, didn't think it was a good idea to be named after a Roman god so he became John II.
-- The last pope to keep his name: Marcello Cervini, elected in 1555, called himself Marcellus II. His mother must have been happy.
-- Two popes named Peter changed their name out of respect for the first pope: John XIV (983-84) and Sergius IV (1009-12).
-- There have been three father-son combinations, the last when Sergius III (904-911) was later followed by his illegitimate son, John XI (931-35).
-- The first pope to live in the Vatican: Nicholas III (1277-80).
-- Why do popes wear white? It started when a Dominican priest, an order known for its distinctive white habit, was elected Innocent V in 1276 and kept his old clothes. The white cassock became standard for all popes after another Dominican, Pius V, was chosen in 1566.
-- Three popes were under the age of 25. The last was Pope Gregory V, who was 24 when elected in 996.
-- Only three popes were over 80 when elected. The last, chosen by the conclave of 1406, was Gregory XII, at age 81. Benedict XVI was 78 when he was elected in 2005.
-- The last non-Italian before John Paul II was elected in 1978 was Hadrian VI, a Dutchman chosen in 1522. John Paul II was also the first and only Slavic pope.
-- The first pope to travel by airplane: Paul VI (1963-78).
-- The longest reigning pope was, by tradition, St. Peter, the first pope. He is said to have served a term of 35 years, from the death of Jesus to his own crucifixion in Rome when he was in his 60s. Pope Pius IX (1846-1878) comes in second at nearly 32 years. John Paul II went just over 26 years.
-- The shortest papacy belongs to Urban VII, who died after just 12 days in office, in 1590. John Paul I died in 1978 after 33 days.
-- There have been three popes from Africa (all from what is now considered North Africa), the last being Pope Gelasius, who was elected in 492. Gelasius was also the first pope to be called the Vicar of Christ.
-- The first and only pope to have ordered the murder of his predecessor was Sergius III (904-11), who had Leo V killed.
-- If you become pope, you have a 1-in-3 chance of becoming a saint. Out of 265 popes, 81 are saints -- though most pope-saints came in the early centuries of the church, when many were martyrs, which is a fast-track to canonization.
-- The last pope to be recognized as a martyr: Martin I (649-54), he died in exile in Crimea, imprisoned in brutal conditions.
-- Some want the late John Paul II to be known as "John Paul the Great." Three other popes in history have been given that honorific: Leo I (440-61), Gregory I (590-604) and Nicholas I (858-67).
BONUS: Was there really a Pope Joan? No, but it's too good a story not to keep coming up.
Sources: "101 Questions and Answers on Popes and the Papacy," by Christopher Bellitto; "Lives of The Popes: The Pontiffs from St. Peter to John Paul II," by the Rev. Richard P. McBrien; Catholic News Service, Salvador Miranda of Florida International University.