Cardinals from around the world will enter the Sistine Chapel on Wednesday for a secret conclave to elect the next pope, following the death of Pope Francis last month after a 12-year papacy.

A total of 133 cardinal electors under the age of 80 have gathered at the Vatican from more than 70 countries. To be elected, a candidate must receive at least 89 votes — a two-thirds majority — in what is the largest conclave in Church history.

The election comes at a pivotal moment for the Catholic Church, which faces internal divisions, dwindling congregations in the West, and ongoing fallout from the clerical abuse scandal. The new pope will also navigate complex diplomatic challenges amid global political instability.

Experts say the field of potential successors is wide open, with frontrunners emerging from Europe, the United States, Asia, and Africa. More than a dozen names are circulating, including Italian Cardinal Pierbattista Pizzaballa, Hungary’s Cardinal Peter Erdo, and Sri Lanka’s Cardinal Malcolm Ranjith.

Cardinals will begin their day with a pre-conclave Mass at 10 a.m. in St. Peter’s Basilica, presided over by Cardinal Giovanni Battista Re, dean of the College of Cardinals. It will be the final public ceremony before the Church announces the 267th pontiff.

"If we can witness the white smoke that'd be something... that's definitely once in a lifetime," US tourist Luke Vanderburgh told AFP on Tuesday.

The voting process begins in the afternoon. At 3:45 p.m., the cardinals will leave their lodgings at the Santa Marta guesthouse and Santa Marta Vecchia and proceed to the Pauline Chapel of the Apostolic Palace for prayer at 4:30 p.m.

They will then enter the Sistine Chapel, under Michelangelo’s famed frescoes, for what the Vatican has described as “one of the most secret and mysterious events in the world.” Once inside, the cardinals will swear an oath of secrecy and obedience, pledging to serve faithfully if elected.

Italian Cardinal Pietro Parolin, the Church’s secretary of state and the senior elector, will invoke divine guidance.

Under the frescoed ceiling, Parolin will call on God to grant the cardinals “the spirit of intelligence, truth and peace.” He will then lead them in the Latin hymn, “Veni, Creator Spiritus.”

Once the order “Extra omnes” — “Everyone out” — is declared, only the cardinal electors remain. Each then casts a vote using a paper ballot marked “Eligo in Summum Pontificem” (“I elect as Supreme Pontiff”), placing it into a silver plate and tipping it into an urn beneath Michelangelo’s Last Judgment.

Traditionally, just one ballot is cast on the first evening. The ballots are then burned with chemicals to produce colored smoke — black for no result, white when a new pope is chosen.

Outside in St. Peter’s Square, hundreds of faithful are expected to gather, eyes fixed on the chapel chimney. A result could come as early as Wednesday evening.

Both Francis and his predecessor, Benedict XVI, were elected within two days, but Church history offers little certainty. The longest papal election lasted 1,006 days, from 1268 to 1271.

As the process begins, cardinals weigh pressing issues, from financial reform and the role of women in the Church to declining priesthood numbers and the challenge of modernizing the institution.

Though 80 percent of the electors were appointed by Francis, opinions remain divided over whether to continue his legacy or return to a more doctrinally conservative papacy.

We may never know just how close the race is. The cardinals have handed over their phones and pledged total secrecy — the final veil over a centuries-old ritual that continues to shape the course of the Catholic Church.