Hundreds of thousands of people are expected to crowd St. Peter's Square Sunday as newly elected Pope Francis delivers his first prayer address from a window of the papal apartment.
The new pope, formerly Cardinal Jorge Bergoglio of Argentina, is the first Jesuit - a priest of the Society of Jesus - to be elected to lead the global church. He is expected to meet with Argentine President Cristina Kirchner this week.
Francis will be formally installed as head of the Roman Catholic Church Tuesday in a ceremony attended by foreign delegations, including a U.S. delegation led by Vice President Joe Biden, who is Catholic.
The Vatican has said Francis will meet next Saturday with his 85-year-old predecessor, Pope Benedict, who last month became the first pope to resign in 600 years.
Pope Francis, like the 13th century saint whose name he has chosen - St. Francis of Assisi - is noted for his humility and commitment to social issues. On the night he was elected, he shunned the papal limousine and traveled on a bus with the cardinals. He later stopped by a Vatican hotel to pick up his belongings and paid the bill himself.