ROME— Church bells are sounding the alarm for doomsayers and conspiracy theorists here as cardinals convene to elect a new leader for the world’s 1.2 billion Catholics.

According to an ancient prediction, this next pope will be the last.

That theory dates back more than 900 years to when Malachy O’Morgair, the 12th century Archbishop of Ireland, had a vision.

Legend has it that St. Malachy, as he is now known, had a strange dream while on a visit to Rome. He “saw” all the names of the future popes – complete with identifying characteristics – who would rule the church until the end of time. 

Malachy’s “Prophecy of the Popes,” as his vision is called, named Benedict XVI as the 111th – and penultimate – pope. The vision ended with the 112th pope.

---

Clairvoyant or crazy?
In his book, “Life of St. Malachy,” St. Bernard of Clairvaux wrote that Malachy was respected as a clairvoyant who predicted the exact day and hour of his own death.  At least one 20th century pope, Pius X, was convinced Malachy’s vision was divine, according to Rafael Merry del Val, his biographer.

But theologians and clerics argue there was never an authentic written manuscript. Malachy’s list was curiously discovered in 1590 in the Vatican archives, hundreds of years later.

“There is no historical foundation at all to St. Malachy’s list,” said Roberto Rusconi, professor of the History of Christianity at Rome’s University. “Malachy’s gift was to make other people believe in his predictions.”

Others have taken hold of Malachy’s list and compared it with history.

The first pope, according to the list, would be “from a castle on the Tiber” – for believers, that was clearly Pope Celestine II who was born on the shores of the Tiber River.

Pope Benedict was apparently described as “glory of the olives” and doomsayers point to his choice of the name Benedict, since the founder of the Benedictine Order was also known as Olivetans.

And in Malachy’s vision, the last pope – who will soon be elected – is described this way: “in extreme persecution, the seat of the Holy Roman Church will be occupied by Peter the Roman…”

While none of the Italian Cardinals are called Peter, one favorite to become Pope is Cardinal Peter Turkson of Ghana.

Nostradamus: a comet and a lightning bolt
If that was not enough to send shivers down a few spines, Nostradamus, the 16th century French astrologer and seer, predicted much the same as Malachy. 

Nostradamus, a mild-mannered healer, was content to mix potions until the Italian-born French queen, Catherine de Medici, raised his profile from physician to prophet. 

Nostradamus warned that the next-to-last pope would “flee Rome in December when the great comet is seen in the daytime.” 

Taking into account the calendar months were different hundreds of years ago, Nostradamus wasn’t so far off. The Comet ISON, with its 40,000 mile-long tail, has been visible the past couple months as Benedict prepared to abdicate and leave Rome for his temporary home in Castel Gandolfo.

And for those well-versed in the language of brimstone and fire, the signs could not have been more transparent when just hours after Benedict announced he would abdicate, a bolt of lightning struck St. Peter’s Basilica, the very heart of Christianity. A few days later a shower of meteorites fell and devastated a village in Russia.

Cynics shrugged all this off as natural phenomena, while the doomsayers suffered from one more dose of existential angst. 

In St. Paul Outside the Walls, another major cathedral in Rome, medallions line the walls with the names of every pope and the dates of his papacy.  Legend says that when all the medallions are full, the world will finally end.  On the walls of St. Paul’s, there are still some empty spaces.

Perhaps the end isn’t so near.

Related:

Riots, revenge and royal rigging: A history of controversial conclaves

Will Catholics embrace change? The view from one parish in Rome

Full coverage of the papal abdication from NBC News

ROME — The papal conclave to elect the new leader of the world's 1.2 billion Catholics will begin on Tuesday afternoon, a Vatican spokesman announced.

Cardinals will enter the closed meeting after holding a special Mass in St. Peter's Basilica in the morning, Father Federico Lombardi said in a statement Friday.

---

Apart from eating and sleeping, they will not be allowed to leave the conclave until they have chosen who will succeed Pope Benedict XVI, who announced his abdication on Feb. 10 and formally ended his papacy on Feb. 28, citing his increasing physical frailty.

Cardinals have been holding closed-door meetings this week in Rome to plan a date for the conclave.

Earlier Friday, Lombardi confirmed that all of the 115 cardinals taking part in the conclave — in which a series of closed ballots is held in the Sistine Chapel until the new pontiff is chosen — were now in Rome.

On Thursday, reporters were shown images of preparation work being carried out at the Vatican, including the installation of the chimney stack through which white smoke will flow once a pope has been elected.

Related:

Riots, revenge and royal rigging: A history of controversial conclaves

Will Catholics embrace change? The view from one parish in Rome

Full coverage of the papal abdication from NBC News

 

This story was originally published on Fri Mar 8, 2013 7:19 AM EST

Updated at 6:41 p.m. ET: When the next Papal Conclave meets behind closed doors to replace the retiring Pope Benedict XVI, the United States will have an unprecedented voice in the process.

Eleven cardinal electors, almost 10 percent of the conclave, will be Americans -- the largest share the country has ever had, even though it has historically had a large Catholic population.

The retiring pope gets credit for the greater influence of the U.S.

---

Last year, he named three new American cardinals, increasing the U.S. total to 19. Only 11 will be electors because in order to vote in the papal election, the cardinals must be under 80 when the pope being replaced dies or leaves his seat.

With 11 votes, the U.S. is now the second-largest bloc, behind only Italy, which has 28 electors, according to the Holy See press office at the Vatican. Germany is third, with six. The new pontiff is expected to be elected by the end of March, according to Vatican officials.

Cardinal Timothy Dolan, the archbishop of New York who was elevated to cardinal last year, is considered a longshot candidate to succeed the pope.

When asked about the qualities necessary for the next pope, Dolan told TODAY that "a good place to start would be to look at Pope Benedict."

He added: "There's a learning, a savviness about the world, there's a theological depth, there's an unquestionably personal piety and holiness, there's a linguistic talent, there's a knowledge of the church universal."

When asked whether he would be allowed to vote for himself, Dolan laughed. "Crazy people cannot enter the conclave," he joked.

The shift in power toward the U.S. “reflects the vitality of the Catholic Church in the United States,”  John Paul II biographer George Weigel said in November.

"But I don’t think it likely that any American will be elected pope for as long as the United States remains the world’s pre-eminent power," he added.

Alessandro Speciale, Vatican correspondent at Religious News Service, echoed Weigel’s opinion, adding that “coming from the world’s only superpower could still be seen as a negative factor in a global church.”

What the increasing U.S. presence among the cardinal electors might mean is that Benedict XVI was very much aware that Catholicism is no longer a predominantly European religion.

The U.S. has as many as 78 million Catholics, according to the Center for Applied Research in the Apostolate at Georgetown University. For comparison’s sake, Italy, despite having the largest share of electors and being primarily Catholic, has a total population of fewer than 61 million residents, according to World Bank estimates from 2011.

"It remains to be seen whether this numerical weight will actually translate into influence at the conclave," Speciale said in November. "Though national links are powerful, many other factors ... play into the secret voting at the Sistine Chapel."

Some experts have suggested that the next pope might be from Latin America.

Reuters noted Monday that Latin America now "represents 42 percent of the world's 1.2 billion-strong Catholic population, the largest single block in the Church, compared to 25 percent in its European heartland."

Archbishop Gerhard Mueller, who now holds the pope's old post as head of the Congregation for the Doctrine of the Faith, is among the senior Vatican officials to suggest that it might be Latin America's turn.

"I know a lot of bishops and cardinals from Latin America who could take responsibility for the universal Church," he told Duesseldorf's Rheinische Post newspaper in December.

Cardinal Roger M. Mahony, the retired archbishop of Los Angeles, announced in a statement Monday that he will help pick the next pope: "I look forward to traveling to Rome soon to help thank Pope Benedict XVI for his gifted service to the Church, and to participate in the Conclave to elect his successor."

Mahony's announcement that he'll participate in the decision came despite documents revealing he was complicit in protecting priests accused of sex abuse during his tenure as head of the Archdiocese of Los Angeles.

Related:

Pope Benedict XVI to step aside on Feb. 28

'Heavy heart but complete understanding': Pope's resignation stuns church leadership

From prisoner of war to pontiff: A timeline of Pope Benedict XVI's life