May 7 (UPI) — As many as 250 Catholic cardinals gathered in the Vatican ahead of the start of a conclave Wednesday afternoon to elect a new pope, with the result from the first round of voting expected within hours.

The process of electing a new pontiff to replace Pope Francis, who died April 21 at the age of 88, was scheduled to get underway at 5:30 p.m. local time when members of the College of Cardinals enter the 15th century Sistine Chapel where they will remain sequestered, voting up to four times daily until they reach a decision.

All cardinals have a say in the proceedings but only 133 can vote in the secret balloting beneath Michelangelo’s Last Judgment masterpiece, with a two-thirds majority, 89 votes, required for a candidate to be elected.

The outside world is kept updated of progress — cardinals are not permitted to communicate with anyone except fellow conclave members — through smoke signals from a specially installed chimney on the roof.

The first of those post-vote signals is expected Wednesday evening, with the release of black smoke from burning spent ballot papers, indicating no decision has been reached, while white smoke will proclaim a new pope.

White smoke from the first round is unlikely as it has not occurred in centuries.

The past two conclaves, which produced Pope Benedict and Pope Francis in 2005 and 2013 respectively, took less than 36 hours, but conclaves in previous centuries have lasted for weeks or months with some cardinals dying before a decision was reached.

Insiders told The Independent that support was coalescing around four main contenders, including Vatican Secretary of State Pietro Parolin, Hungary’s Peter Erdo, Jean-Marc Aveline of France and the Latin Patriarch of Jerusalem, Pierbattista Pizzaballa.

But as many as a dozen others are in the running to become the 267th pope, including Archbishop of Bologna Matteo Zuppi, Luis Antonio Tagle of the Philippines and Peter Turkson of Ghana.

The man who will very much depend on the late Pope Francis’ dominant so-called “Bergoglian” faction opts to back an alternate candidate, someone seen as likely to pursue his progessive agenda, or the status quo candidate, Parolin.

The day kicked off with a mass for the election of pontiff in St. Peter’s Basilica, led by the Dean of the College of Cardinals, Giovanni Battista Re, Dean of the College of Cardinalsver which was attended by 5,000 people, the Vatican said in a news release.

Shortly after 4:30 p.m., the 133 Cardinal electors will gather in the Pauline Chapel to pray the Litany of the Saints, ahead of a procession into the nearby Sistine Chapel.

The conclave process dates back 750 years, according the Vatican, and was first held in the Sistine Chapel 1492 but only became its permanent home in 1878. The Vatican was an early adopter of democracy, implementing secret written ballots for the conclave in 1621.

Argentine-born Francis, who died of a stroke and heart failure last month after a bout with double-pneumonia, ended a 13-centuries-long run of European-born pontiffs. The election in 1978 of the Archbishop of Krakow, Poland, John Paul II, broke a 455-year-long run of all-Italian popes. He was postumously canonized by Francis in 2014.