"I like him because he loves the poor," said 7-year-old Pietro Loretti, who came from his home in Barletta in southern Italy to attend the Mass. Another child, 9-year-old Benedetta Vergetti from Cervetri near Rome, also skipped school to attend. "I like him because he's sweet like my dad," she said.
The Argentine native is the first pope from Latin America and the first named for the 13th-century friar St. Francis of Assisi, whose life's work was to care for nature, the poor and the most disadvantaged.
In Buenos Aires, thousands of people packed the central Plaza de Mayo square to watch the ceremony on giant TV screens, erupting in joy when Francis called them from Rome, his words broadcast over loudspeakers.
"I want to ask a favor," Francis told them in Spanish. "I want to ask you to walk together, and take care of one another. ... And don't forget that this bishop who is far away loves you very much. Pray for me."
Back in Rome, Francis was interrupted by applause as he declared his role as the leader of the world's 1.2 billion Catholics was to open his arms to "the whole of humanity, especially the poorest, the weakest, the least important, those whom Matthew lists in the final judgment on love: the hungry, the thirsty, the stranger, the naked, the sick and those in prison."
"Today, amid so much darkness we need to see the light of hope and to be men and women who bring hope to others," he said. "To protect creation, to protect every man and every woman, to look upon them with tenderness and love, is to open up a horizon of hope.
It is to let a shaft of light break through the heavy clouds."
After the celebrations die down, Francis has his work cut out as he confronts a church in crisis.
Retired Pope Benedict XVI spent his eight-year papacy trying to reverse the decline of Christianity in Europe, without much success. While growing in Africa and Asia, the Catholic Church has been stained in Europe, Australia and the Americas by sex abuse scandals.
Closer to home, Francis is facing serious management shortcomings in a Vatican bureaucracy in dire need of reform.
Francis hasn't indicated how he might tackle those greater problems, focusing instead on messages and gestures that signal a total shift in priority and personality from his German theologian predecessor.
On Wednesday, Francis may reveal some of his ecumenical intentions, as he holds an audience with Christian delegations who attended his installation. On Friday, he will put his foreign policy chops on display in an address to the ambassadors accredited to the Holy See.
He plans to call on Benedict at Castel Gandolfo, the papal retreat south of Rome, on Saturday, and the next day to celebrate Palm Sunday Mass in St. Peter's Square.
Next week, Francis presides over all the rites of Holy Week, capped by Easter Sunday Mass on March 31, when Christians mark the resurrection of Christ, an evocative start to a pontificate.
