The death of Pope Francis on Monday means the Roman Catholic Church will soon begin the process of selecting a new pontiff.
That ancient and mysterious undertaking known as the "conclave" invariably draws speculation over who will be chosen to lead the church and its 1.4 billion adherents worldwide.
But the hushed affair also produces intense public interest in the conclave itself. What exactly happens after the Sistine Chapel doors close and the highest-ranking members of church leadership get down to the business of electing the next Bishop of Rome?
Papal elections weren't always this secretive. But after one particularly long period in the 13th century with no pope, the church imposed new rules that thrust the election — literally — behind closed doors. That aligned with the theological concept that God was acting through the cardinals during the conclave, but it also served to keep the electors focused on their decision and bar any meddling government officials from influencing the vote.
In the modern era of social media, when you can travel pretty much anywhere on your phone, the conclave with its clandestine deliberations and archaic trappings remains one of those institutions that feels like a vestige of a former era. Here's how it began.
Where did the word come from?
The word "conclave" is a Latin noun dating back to ancient Rome meaning a locked room, typically used to store valuables or imprison someone, according to Anthony Lo Bello, who wrote Origins of Catholic Words: A Discursive Dictionary.
Two roots come together to form conclave: cum meaning 'with' and clavis meaning 'key'.
"It's used by [Roman orator] Cicero and [Roman poet] Horace, and that was even before the time of Christ," Lo Bello said. "It's a very old word, antedates the Catholic religion."
It wasn't until the Middle Ages that the word conclave came into regular use to describe papal elections.
In the late 13th century, the Catholic Church went through a nearly three-year period without a pope. Pope Gregory X was finally selected in 1271, and several years later he issued a papal bull known as Ubi periculum setting some rules for the organization of future papal elections, or conclaves.
Under that law, the cardinals were to meet in secret to select the pope's successor. They were each allowed one or maybe two servants and received food through an opening in a window. If they didn't elect a new pope within eight days, their rations were to be cut down to only bread, water and wine.
There were a few reasons for the sequestration of cardinal electors, says Miles Pattenden, an Oxford University professor who specializes in the history of the Catholic Church.
"The theology behind the conclave, the idea behind it, is that God through the Holy Spirit descends on the cardinals and inspires their choice," Pattenden said. "And in order for that to happen and for it to be believed and believable, the cardinals have to be separated away from everybody else while they're making this decision."
A sealed-off conclave also served to keep any procrastinating prelates on task, following the lengthy papal vacancy that preceded Pope Gregory X's election. (At one point during that period, villagers in Viterbo, Italy, got so fed up with the prolonged deliberations that they removed the roof of the palace where the cardinals had gathered, exposing the holy men to the elements in a bid to hasten their decision.)
Additionally, the secrecy of the conclave prevented any political leaders with an interest in the outcome of the election from attempting to sway the cardinals' votes once the meeting had started.
How has the word been used over time?
The word conclave has gone from meaning simply a locked room in ancient Rome to denoting the very particular process by which a new Catholic pope is elected. Like the word's definition, the institution of the papal conclave has shifted over the centuries.
Pope Gregory X's rules for the conclave weren't always easy to follow and, as a result, were sometimes changed or ignored. Electors at the 1351 conclave were allowed two servants instead of one and given a three-course menu for the entire event. Hundreds of people were present for the 1549–1550 conclave, even though only around 50 of them were cardinals, Pattenden said.
There was another persistent challenge posed by the cloistered nature of the conclave: personal hygiene.
Pattenden said his research into 16th- and 17th-century papal conclaves found references to "how disgusting it was being inside there, how badly the place smelled, how susceptible it was to disease, especially if the conclave was taking place in summer."
Some of the electors left the conclave sick, often gravely. "The cardinals simply had to have a more regular and comfortable way of living because they were old men, many of them with quite advanced disease," Pattenden added.
In 1996, Pope John Paul II decided that cardinal electors during future conclaves would be housed in the Domus Sanctae Marthae, a guesthouse built in the same year in Vatican City. Previously the cardinal electors slept on cots in rooms or "cells" connected to the Sistine Chapel, the BBC reported. (The first papal conclave in the Sistine Chapel was in 1492, and every conclave since 1878 has been held there.) The guesthouse has been referred to as a "three-star hotel."
Why does the word matter today?
Even now, papal conclaves are highly secretive. Cardinal electors taking part in the upcoming conclave will have to swear an oath of secrecy. During voting, the doors of the Sistine Chapel will be locked and the Swiss Guard will stand at attention outside.
That has only intensified the public's curiosity about the process, a curiosity captured in popular culture by books and films like last year's Conclave starring Ralph Fiennes.
Though the modern era has expanded humanity's knowledge in many ways, the papal conclave remains an enigma.
"Some of the mystery does come from the closed nature of the conclave itself," Gregg Gassman, a librarian who edits the Pontifacts podcast, told NPR. "It's fascinating."
If history is any guide, the only signal that will come out of the conclave at the Sistine Chapel following the death of Pope Francis will be the smoke that billows from the chimney — black if there's no winner, white if there is.
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