VATICAN CITY — Jorge Mario Bergoglio of Argentina became the first pope from the Americas and the first from outside Europe in more than a millennium in an election that recognized a shift in the Roman Catholic Church's center of gravity while maintaining its conservative theology.
The new Pope Francis, the 266th in the church's history, is immediately confronted with daunting challenges. His flock is growing rapidly in some parts of the globe but is disenchanted and shrinking elsewhere. The Vatican bureaucracy is widely thought to need sweeping reform and the church is still struggling with the legacy of its sex abuse scandal.
But his election represented a gentle earthquake for an institution steeped in tradition: a major departure geographically, yet a continuation theologically with his conservative predecessors, the late John Paul II and Benedict XVI, whose surprise resignation last month threw the church into uncertainty.
The cardinals who elected Bergoglio, 76, after just 24 hours of voting chose a man known for his striking humbleness. The son of Italian immigrants — a reassurance for those worried about the church abandoning its European roots completely — he has served since 1998 as archbishop of Buenos Aires, where he cultivated a reputation for competent administration, a willingness to speak out on controversial national issues and an austere lifestyle belying his prestigious position.
His first act was to pick a papal name that analysts say reflects the intended focus of his reign: an emphasis on the humility and concern for the poor and the marginalized that was exemplified by St. Francis of Assisi. Francis was also the name of a prominent 16th century Jesuit, the highly intellectual order to which Bergoglio belongs, who preached the Gospel in Asia.
The new pope is also seen as an outsider who may be able to usher in the internal reform and cleanup that critics say the Vatican desperately needs after years of factionalism and scandal. But some questioned whether his age and personality would make him a transitional figure unlikely to leave a distinctive legacy.
Bergoglio's self-effacing manner seemed evident from the moment of his unveiling, when he stepped from behind red velvet curtains onto the central balcony of imposing St. Peter's Basilica about 8 p.m. He waved with one hand to the crowd of tens of thousands below in St. Peter's Square, looking almost embarrassed as a small smile played on his bespectacled face.
"You know that the duty of the conclave was to give Rome a bishop," he said, referring to the pontiff's role as bishop of that city. "It seems that my brother cardinals picked him from almost the ends of the Earth. But here we are! I thank you for the warm welcome."
He exhorted his listeners to foster love, trust and unity.
Cheers and jubilant shouts of "Viva il Papa!" rose from the crowd. Many had waited for hours in the cold and rain to watch for the white smoke billowing from the Sistine Chapel, the signal of a conclusive vote inside, and to see who would appear on the balcony following the traditional Latin announcement of "Habemus papam" — "We have a pope."
"To have a guide again after this strange period is wonderful," said Salvatore Califano, 42, an Italian navy official. "From his speech, he felt like a normal person, and that really touched me."
The new pope will be officially installed Tuesday on the feast day of St. Joseph, the patron saint of the church. On Thursday, Francis will conduct a Mass in the Sistine Chapel for the cardinals, in a televised service that could help burnish his credentials as a gentle leader.
President Obama hailed Bergoglio "as a champion of the poor and the most vulnerable among us" and his choice as a wise nod to changing demographics. Latin America is home to about 40% of the world's Catholics.
"As the first pope from the Americas, his selection also speaks to the strength and vitality of a region that is increasingly shaping our world," Obama said, "and alongside millions of Hispanic Americans, those of us in the United States share the joy of this historic day."
Congratulations were more restrained from Argentine President Cristina Fernandez de Kirchner, with whom Bergoglio has clashed on issues such as same-sex marriage.
Bergoglio's selection came after five rounds of voting and took only a few hours longer than the last conclave needed to choose Benedict, in 2005 — when Bergoglio was the runner-up, according to a credible account of those proceedings.
The speed showed that support quickly coalesced behind him, despite reports of increasing divisions among the cardinals entering the conclave. Vatican watchers had speculated over possibly opposing camps that wanted a charismatic, pastoral figure to spread the Gospel across the world or a more managerial leader capable of purging the Vatican bureaucracy of dysfunction and alleged corruption.