The Catholic Church's surprising new leader from "the end of the earth" will hold his first Mass as pope today.
Cardinal Jorge Mario Bergoglio, 76, a pioneer pope from Argentina who took the name Francis, is a pastor rather than a manager, tasked with resurrecting a church and a faith in crisis.
The archbishop of Buenos Aires is the first pontiff from the New World and the first non-European since the Middle Ages. He is the first pope from the Americas, the first Jesuit and the first named Francis, after St Francis of Assisi, the humble friar who dedicated his life to helping the poor. The last non-European pope was Syria's Gregory III from 731-41.
Francis will celebrate his first Mass as pope in the Sistine Chapel today and will be installed officially on Tuesday.
One of his first foreign trips is expected to be World Youth Day in Rio de Janeiro in July, an event that will energise the continent, given their native son will be presiding.
Vatican spokesman the Rev Federico Lombardi, also a Jesuit, said he was particularly stunned by the election given that Jesuits typically shun positions of authority in the church, instead offering their work in service to those in power.
But he said that in accepting, Francis must have felt it "a strong call to service", an antidote to all those who speculated that the papacy was about a search for power.
"You know that the work of the conclave is to give a bishop to Rome," the new pontiff said as he waved shyly to the tens of thousands who braved the cold rain in St Peter's Square last night.
"It seems as if my brother cardinals went to find him from the end of the earth, but here we are. Thank you for the welcome."
Francis, said to have finished second when Pope Benedict XVI was elected in 2005, was chosen on just the fifth ballot to replace the first pontiff to resign in 600 years. In the past century, only Benedict, John Paul I in 1978 and Pius XII in 1939 were elected faster.
His election elated Latin Americans, who number 40% of the world's Catholics but have long been under-represented in the church leadership. Drivers honked their horns in the streets of Buenos Aires and television announcers screamed with elation at the news.
"It's a huge gift for all of Latin America. We waited 20 centuries. It was worth the wait," said Jose Antonio Cruz, a Franciscan friar at the St Francis of Assisi church in the colonial Old San Juan district in Puerto Rico.
The new pontiff brings a common touch. The son of middle-class Italian immigrants denied himself the luxuries that previous cardinals in Buenos Aires enjoyed. He lived in a simple apartment, often took the bus to work, cooked his own meals and regularly visited slums that ring Argentina's capital.
He considers social outreach, rather than doctrinal battles, to be the essential business of the church.
"As a champion of the poor and the most vulnerable among us, he carries forth the message of love and compassion that has inspired the world for more than 2,000 years - that in each other, we see the face of God," US president Barack Obama said.
But as the 266th pope, Francis inherits a Catholic church in turmoil, beset by the clerical sex abuse scandal, internal divisions and dwindling numbers in parts of the world where Christianity had been strong for centuries.
Francis is sure to bring the church closer to the poverty-wracked region, while also introducing the world to a very different type of pope, whose first words were a simple: "Brothers and sisters, good evening."
He asked for prayers for himself and for Benedict, whose stunning resignation paved the way for his election.
Francis spoke by phone with Benedict, who has been living at the papal retreat in Castel Gandolfo, and told cardinals he planned to visit the retired pontiff tomorrow, according to US cardinal Timothy Dolan.
Earlier, shouts of joy went up from the throng huddled under a sea of umbrellas when plumes of white smoke poured out of the copper chimney atop the Sistine Chapel a few minutes past 7pm. "Habemus Papam!" (We have a pope!), they chanted as the bells pealed in St Peter's Basilica and churches across Rome.
After what seemed like an endless wait of more than an hour, they cheered again when the doors to the loggia opened and a cardinal stepped out and revealed the identity of the new pontiff, using his Latin name, then announced he would be called Francis.
In choosing to call himself Francis, the new pope was associating himself with the much-loved Italian saint from Assisi known as a symbol of peace, poverty and simplicity.
St Francis was born to a wealthy family but renounced his wealth and founded the Franciscan order of friars; he wandered about the countryside preaching to the people in very simple language.
He was so famed for his sanctity that he was canonised just two years after his death in 1226.
St Francis Xavier is another important namesake. One of the 16th-century founders of the Jesuit order, the legendary missionary spread the faith as far as India and Japan.
In choosing Francis, the cardinals clearly decided that they needed a seasoned, popular and humble pastor who would draw followers to the faith and help rebuild a church stained by scandal.
Catholics are still buzzing over his speech last year accusing fellow church officials of hypocrisy for forgetting that Jesus Christ bathed lepers and ate with prostitutes.
His legacy includes his efforts to repair the reputation of a church that lost many followers by failing to openly challenge Argentina's murderous 1976-83 dictatorship. His own record as the head of the Jesuit order in Argentina at the time has been tarnished as well.
FRANCIS' FIRST PAPAL SPEECH IN FULL
Here is the Vatican's official English translation of Pope Francis' speech, Urbi et Orbi, delivered in Italian from the central balcony of St Peter's Basilica.
Brothers and sisters, good evening!
You know that it was the duty of the conclave to give Rome a Bishop. It seems that my brother cardinals have gone to the ends of the earth to get one... but here we are... I thank you for your welcome. The diocesan community of Rome now has its Bishop. Thank you! And first of all, I would like to offer a prayer for our Bishop Emeritus, Benedict XVI. Let us pray together for him, that the Lord may bless him and that Our Lady may keep him.
(Our Father... Hail Mary... Glory Be... )
And now, we take up this journey: Bishop and People. This journey of the Church of Rome which presides in charity over all the Churches. A journey of fraternity, of love, of trust among us. Let us always pray for one another. Let us pray for the whole world, that there may be a great spirit of fraternity. It is my hope for you that this journey of the Church, which we start today, and in which my Cardinal Vicar, here present, will assist me, will be fruitful for the evangelisation of this most beautiful city.
And now I would like to give the blessing, but first - first I ask a favour of you: before the Bishop blesses his people, I ask you to pray to the Lord that he will bless me: the prayer of the people asking the blessing for their Bishop. Let us make, in silence, this prayer: your prayer over me.
Now I will give the blessing to you and to the whole world, to all men and women of goodwill. (Blessing)
Brothers and sisters, I leave you now. Thank you for your welcome. Pray for me and until we meet again. We will see each other soon. Tomorrow I wish to go and pray to Our Lady, that she may watch over all of Rome. Good night and sleep well!