On Monday, Pope Francis died at the age of 88. Attention has already turned to who will succeed him. But anyone who claims to know who the next pope will be is just speculating. Even the

most savvy and knowledgeable expert can’t offer more—thanks to the secretive nature of the selection process. For roughly 750 years, the College of Cardinals has chosen popes at closed

conclaves where participants are locked in and completely cut off from the outside world. Every cardinal and anyone else involved in the sealed conclave—there are a small number of cooks,

medical staff, and clerical support locked in with the electors—takes a vow of secrecy never to talk about what happened without a pope’s permission. The penalty for violating this pledge is

since 1788, there have only been 16 papal conclaves during that period. And perhaps the only lesson from these 16 choices is to expect the unexpected.  For the first millennium of

Christianity, the Catholic Church selected popes in one of two fashions. Either a cheering Roman crowd picked Catholics’ next spiritual leader, or a group of local clergy and powerful

families got together and made a choice.  The locked conclave did not become the method for papal selection until the 13th century. The process changed because the cardinals infuriated the

people of Viterbo, Italy by taking nearly three years to choose a successor to Pope Clement IV, who had died in their town. At that time, there were not many cardinals so they tended to

travel with the pope and elected a successor wherever the prior pope had died. The fed up laypeople finally locked the cardinals up in an effort to hasten the process. The tactic worked. The

cardinals quickly made a selection once they were behind lock and key. Their choice, Gregory X, thought he’d learn from a good example. In 1274, the church added the conclave into the

official rules for papal selection: henceforth, cardinals would be locked up until they chose the next Catholic leader.  Yet, deciding in secret didn’t originally mean the _total_ secrecy

that characterizes modern conclaves. In the Vatican archives, the church historian Frederic J. Baumgartner discovered vote tallies from the early modern conclaves.  By 1800, however, church

leaders decided that they should burn all ballots and notes from conclaves. Pope Pius VI had died as Napoleon’s prisoner and the cardinals were trying to protect the church’s independence.

Some of the cardinals didn’t want their local government officials to know how they’d voted during an era of shifting national alliances. Over time, this practice led to a new tradition: the

cardinals would burn the ballots with substances to make the smoke black to indicate no pope was elected and white to indicate success. __In the 16 more secretive conclaves since 1800, one

pattern has emerged: more often than not, the choices typically don’t come from the bandied-about names of _papabili_ (literally, “pope-able”). It’s in fact rare for that to happen: In 1963,

Vatican watchers were pretty sure the conclave would select Milan’s Cardinal Giovanni Montini, and that’s precisely what happened: he became Paul VI. The saying “he who enters the conclave

as pope leaves as a cardinal” was wrong in this case.  But 1963 was an exception. That became clear when Paul VI died in 1978—the year of three popes. The conclave to replace him chose

Cardinal Albino Luciani, who took the hybrid name John Paul I. In a shock, he died a month later (likely of a heart attack). That meant a second conclave, and this time the cardinals chose a

name on nobody’s radar: Krakow’s Cardinal Karol Wojtyla, who took the name John Paul II. At least in this case, one cardinal kept his vow of silence about how that came about. “I would like

to tell you everything. It would thrill you,” said St. Louis’s Cardinal John Carberry. “But I can’t.” The second 1978 gathering proved to be the last conclave of the 20th century. John Paul

II remained pope until his death in 2005. Given his 27-year tenure, observers expected the cardinals to replace John Paul II with an older successor. There was a sense that another very

lengthy papacy was too much. Additionally, the final years of John Paul II’s papacy had been crushed by Parkinson’s disease. There was a real need for someone with administrative skills. The

curia—the Vatican’s bureaucracy— was in terrible shape and it would take someone who knew how things worked to fix it. That person ended up being the German Cardinal Joseph Ratzinger, who

had run the Vatican’s doctrinal office with a firm hand for almost all of John Paul II’s papacy. Nevertheless, Ratzinger’s name appeared on very few _papabili_ lists and when it did, it was

quite low, likely because he was considered a bit _too_ old at 78. That meant his election as Benedict XVI was both surprising and unsuprising. Yet, he didn’t wrangle the curia into

efficiency, and a great desire for change percolated among the cardinals. When Benedict XVI unexpectedly resigned in 2013, what followed was something like the second 1978 conclave, which

produced a choice on almost no one’s list. Perhaps that wouldn’t have been the case had observers had more insight into the 2005 conclave, which we’ve gotten from whispers and hints in

memoirs and interviews. Some cardinals have stepped very close to the line of breaking their vow of secrecy—or even broken it behind the cloak of anonymity. One kept a secret diary and

shared it with an Italian journalist. That diary indicated that while Ratzinger always led the vote in the 2005 conclave, Cardinal Jorge Mario Bergoglio of Buenos Aires had roughly 40 votes,

nowhere near the required two-thirds majority of the 115 electors, but a substantial number nonetheless. Perhaps he was too abrupt a break from John Paul II at that moment, so the cardinals

made the safe choice with Ratzinger, whose papacy proved to be a coda to that of his predecessor. But the 2013 conclave returned to Bergoglio, who became Pope Francis, demonstrating that

there is such a thing as a second act in conclave politics. Some have argued that Francis has loaded the college of cardinals with his men to ensure his agenda will continue after he is

gone. Yet, in truth, Pope Francis simply did what every other pope (or monarch, world leader, or even CEO) would do: surrounded himself with like-minded people. Historically, that hasn’t

guaranteed a like-minded successor, as demonstrated by the choice of the Polish John Paul II after 455 years of Italian popes, and the selection of the decentralizing Francis after 35 years

of more monarchical papacies. History doesn’t offer a specific pattern to help observers predict the conclave set to take place. It seems logical that the conclave may opt for the second

consecutive pope from south of the Equator, where the church is flourishing, rather than north where it is faltering. But as past conclaves have illustrated, frequently the choice is

unexpected. That’s the final lesson of studying the history of conclaves. _Christopher M. Bellitto is professor of history at Kean University in Union N.J. His books include 101 Questions

and Answers on Popes and the Papacy (Paulist Press) and his latest, Humility: The Secret History of a Lost Virtue (Georgetown University Press, 2023)._ _Made by History takes readers beyond

the headlines with articles written and edited by professional historians. Learn more about Made by History at TIME here. Opinions expressed do not necessarily reflect the views of TIME

editors. _