The Sistine Chapel was closed off to outsiders for the last papal election, which was sparked by the resignation of Pope Benedict XVI. (Osservatore Romano/Associated Press)

Cardinals from around the world line up in the Vatican's Sistine Chapel March 12, 2013, to take their oaths at the beginning of the conclave to elect a successor to Pope Benedict XVI. The following day, on the fifth ballot, they elected Cardinal Jorge Mario Bergoglio of Buenos Aires, Argentina, who chose the name Francis. The cardinals will again gather May 7, 2025, to elect a a successor to Pope Francis, who died April 21. -- CNS photo/Vatican Media

CNS photo/Vatican Media

White smoke billows from the chimney on the roof of the Sistine Chapel indicating that the College of Cardinals elected a new Pope back on March 13, 2013 in Vatican City, Vatican. Pope Benedict XVI's successor - the 266th Pontiff - was selected by the College of Cardinals in Conclave in the Sistine Chapel. Peter Macdiarmid / Getty Images