VATICAN CITY — Pope Benedict XVI broke centuries of precedent Monday by resigning the papacy because of issues of old age, surprising the globe's 1.1 billion Roman Catholics and prompting speculation that the next pope will be the first non-European to lead the church in modern times.
Once the shock wore off, church leaders and followers praised Benedict's legacy on such matters as liturgy and dealing with the church's sex-abuse scandals, but also began to debate the merits of a younger pope who might reign for decades and be more representative of the global church, which has had its biggest recent membership increases in South America, Africa and Asia.
"Europe today is going through a period of cultural tiredness, exhaustion, which is reflected in the way Christianity is lived," Bishop Antonio Marto of Fatima, Portugal, told reporters. "You don't see that in Africa or Latin America, where there is a freshness, an enthusiasm about living the faith.
"Perhaps we need a pope who can look beyond Europe and bring to the entire church a certain vitality that is seen on other continents," he said.
'This can't be'
The 85-year-old Benedict said his resignation would take effect at the end of February and that he had "repeatedly examined my conscience before God" and had "come to the certainty that my strengths, due to an advanced age, are no longer suited to an adequate exercise" of the papacy.
The message, delivered in Latin and translated into seven other languages, shocked many Catholics, lay and clerical.
"I was like, 'The pope has resigned?'" said Cardinal Thomas Collins of Toronto. The Associated Press quoted Venezuelan churchgoer Alis Ramirez as insisting, "He can't quit like that. This can't be."
The College of Cardinals, the elite group of prelates who elect the pope, will hand steep challenges to the next pontiff.
The ongoing clerical sex abuse scandal has roiled the church for more than a decade and has driven away millions of Catholics, especially in Europe and North America, where the old model of the "ethnic church" and related loyalty also has largely collapsed.
The Vatican is also reeling from another round of scandals over its bank, which led to, among other things, the arrest last year of the pope's butler for leaking documents about financial corruption. Benedict has tried to improve the Vatican's financial management, which has been viewed as corrupt for decades.
Just a few weeks ago, Swiss Cardinal Kurt Koch, who heads the Vatican's department for Christian unity, noted that church's future might lie outside Europe, where its popularity and following has declined over the past decade.
"It would be good if there were candidates from Africa or South America at the next conclave," Cardinal Koch said, according to The Telegraph.
Andreas Dingstad, a spokesman for the Catholic diocese in the Norwegian capital of Oslo, said the time might be right for a "youngish" pope, possibly from the developing world.
"The church is growing most in the south. So I think lots of people will be ready for a pope from Africa, Asia or South America," Mr. Dingstad said. "But who knows; it's the early days still."
Betting under way
Whether the college picks a younger pope or not, Benedict's resignation in the face of ill health also was seen Monday as precedent-setting and important because modern medical technology is likely to make the occasion of a frail but alive pope more common than before.
"For the century to come, I think that none of Benedict's successors will feel morally obliged to remain until their death," Paris Cardinal Andre Vingt-Trois said.
According to news reports, two cardinals from Africa have emerged as top contenders for the papacy:
• Cardinal Francis Arinze. Born in Nigeria, Cardinal Arinze, 80, has been the bishop of Velletri-Segni, a cluster of Roman suburbs, since 2005 — when he succeeded Cardinal Joseph Ratzinger, who became Benedict XVI.
• Cardinal Peter Kodwo Appiah Turkson. Born in Ghana, the 64-year-old cardinal is the archbishop of his native country and is a member of councils focused on evangelization, worship and Catholic education.
About 176 million people in Africa are Catholic, nearly one-third of all Christians across the continent, according to a December 2011 study by the Pew Forum on Religion and Public Life.
British bookmakers offered odds on candidates to replace Benedict, with Cardinals Turkson and Arinze taking lead positions. Speculation turned to other likely contenders among the College of Cardinals, including:
• Cardinal Marc Ouellet. The head of the Vatican's office for bishops was born in Quebec 68 years ago, and has been a cardinal since 2003.
• Cardinal Luis Antonio Tagle. Born in the Philippines, he is the archbishop of Manila and 56 years old. He has been a cardinal since 2012.
• Cardinal Leonardo Sandri. Born in Buenos Aires, Cardinal Sandri, 69, heads the Vatican's Asian churches department.
Next month, the College of Cardinals will hold a conclave, a secret meeting in the Sistine Chapel where cardinals cast ballots to elect a new pope. There will be four votes per day — two in the morning and two in the afternoon.
As per tradition, the ballots are burned after each voting round; black smoke that snakes out of the chimney means no pope has been chosen, while white smoke means a pope has been elected.
All cardinals younger than 80 are allowed to vote, and the conclave must begin 15 to 20 days after Benedict's resignation takes effect Feb. 28. There are 118 cardinals younger than 80 and thus eligible to vote. The group includes 67 who were appointed by Benedict. However, four of them will turn 80 before the end of March. Depending on the date of the conclave, they may or may not be allowed to vote.
Benedict in 2007 passed a decree requiring a two-thirds majority to elect a pope, changing the rules established by John Paul II who had decided that the voting could shift to a simple majority after about 12 days of inconclusive voting. Benedict made the change to prevent cardinals from merely holding out until the 12 days had passed to push through a candidate who had only a slim majority.
The timing of Benedict's announcement is significant: Lent begins this week on Ash Wednesday, the most solemn period on the church's calendar that culminates with Holy Week and Easter on March 31.
By Easter Sunday, the Catholic Church will have a new leader, a potent symbol of rebirth in the church that echoes the resurrection of Christ in its celebration of Easter.
Among Benedict's successes, especially cited among the more orthodox and traditional Catholics, were relaxations on restrictions on celebrating the pre-Vatican II traditional Latin Mass and a streamlined process for incorporating Anglican churches fleeing their own denomination over theological trends such as ordaining women and altering traditional Christian teachings on sexuality.
Benedict's handling of the sex-abuse crisis, though it drew criticism, was also widely considered to be far better than that of his predecessor, Pope John Paul II. Unlike John Paul, he personally met with victims of clergy sex abuse on several of his journeys, including one to the U.S.
He also issued an unprecedented apology to Ireland's Catholics over decades of systematic sex abuse and told guilty clergy that they should "submit yourselves to the demands of justice." Benedict also moved strongly against the Legion of Christ, ordering a full-scale reworking of an order that had enjoyed the favor of John Paul but whose now-repudiated founder had serially abused seminarians and fathered at least three children.
A papal resignation is without recent precedent, but it has happened before. In 1415, Pope Gregory XII resigned at the request of church officials as the first in a series of compromises that helped end the Great Schism, in which there were three different claimants to the papacy. The next elected pope, Martin V, was not selected until after Gregory's death.
Before that, the last uncontested pope to resign was Celestine V, who left the papacy in 1294. Celestine was imprisoned in a castle near Naples by Boniface VIII, his successor, and was so despised that when Italian poet Dante Alighieri wrote "The Divine Comedy" 25 years later, he placed Celestine in Hell's antechamber.
Benedict himself took a more benign view of his predecessor, praying in 2009 at his tomb in L'Aquila, Italy.
• Jennifer Collins reported from Berlin. Cheryl K. Chumley in Washington contributed to this article, which is based in part on wire service reports.