VATICAN CITY - Sunshine glinting off his golden vestments, Pope Benedict XVI summoned centuries of Catholic tradition yesterday, then asked hundreds of thousands of people gathered in St. Peter's Square to join him as he sets out on a new papacy.
"Pray for me that I may learn to love the Lord more. ... Pray for me that I may learn to love his flock more and more," he said during his official Mass of investiture. "Pray for me that I may not flee for fear of the wolves."
That remark struck a poignant note after a week of mixed reactions to the former Cardinal Joseph Ratzinger's election as pope, including some sharply personal criticism.
But in yesterday's crowd, estimated by the Vatican to exceed 350,000, joy fueled the historic moment and was directed toward the man greeted with the chant "Ben-e-dett-o! Ben-e-dett-o!" - the Italian version of his chosen name.
Frances Nwonyi, 35, a Nigerian immigrant living in Rome, said she came to receive one of the first blessings from the new pope, a moment of particular power for her.
"The Holy Spirit is going to touch individuals in different ways," she said of the people gathered in the square. "I believe today there will be a change in my life."
German flags joined banners from the nations of the world in the square. Perhaps the most dominant colors came from the sky-blue and white checkered flags of Bavaria, the region where the pope was born and raised.
Contrails from military jets traced giant circles in the blue Roman sky, a reminder of the heavy security for an event that drew heads of state and other dignitaries from around the world, including Maryland Lt. Gov. Michael S. Steele, Florida Gov. Jeb Bush and Prince Albert II of Monaco.
But the armies on the move yesterday were a different sort - first the press of the faithful and the curious into the square, and then the hundreds of white-robed priests who fanned out to offer communion to the crowd.
The two-hour, 40-minute Mass was a markedly more joyous occasion than the liturgy in the square 16 days earlier, when Pope John Paul II's wooden coffin was visible in the square for the funeral Mass. Yesterday's Mass marked the completion of the age-old transition from one pope to the next.
Still, Pope Benedict made clear once again that he intends to embrace his predecessor's agenda and continue to celebrate Pope John Paul's deep influence on the church.
"At this point, my mind goes back to October 22, 1978, when Pope John Paul II began his ministry here in St. Peter's Square. His words on that occasion constantly echo in my ears: 'Do not be afraid! Open wide the doors for Christ!'" the new pope said.
Pope Benedict, who at 78 is the oldest man elected pope in centuries, was a cardinal that day. He said Pope John Paul's message was aimed at the powerful and the powerless, but especially at the young.
Pope Benedict said that now, as an older, more experienced man, he wanted to repeat the message for young people. "The church is alive," he said at one point. "The church is young."
The pontiff sounded tired at times, his high voice cracking. But he also seemed buoyed by the moment, frequently raising his arms in acknowledgement of the crowd and beaming when he received the Ring of the Fisherman, an ancient symbol of the papacy recalling St. Peter's original trade and the Scripture passage in which Jesus tells his disciples to become fishers of men.
He received dozens of ovations, few louder than when he said, "At this moment there is no need for me to present a program of governance."
For a policy outline, he said, observers should look to the message he delivered to the cardinals Wednesday, when he called for an emphasis on the Eucharist within Catholic life, a greater push for Christian unity, continued interfaith dialogue and a particular attention to evangelizing young people.
But yesterday's homily did reinforce some of those developing themes.
After addressing himself to Catholics, other Christians and "my brothers and sisters of the Jewish people," he signaled his intention to address the whole world.
"Finally, like a wave gathering force, my thoughts go out to all men and women of today, to believers and nonbelievers alike," he said.
That increasingly secular world also inspired the kind of spiritual and cultural critique for which Ratzinger became known during more than two decades in the top tier of papal advisers.
"There is the desert of poverty, the desert of hunger and thirst, the desert of abandonment, of loneliness, of destroyed love. There is the desert of God's darkness, the emptiness of souls no longer aware of their dignity or the goal of human life.
"The external deserts in the world are growing, because the internal deserts have become so vast," he continued.
Ruth Kimmins, 62, an Anglican from Halifax, Nova Scotia, said she found the clear statements of Pope John Paul appealing and has high expectations for his successor.
"He's probably going to be a healer," she said, standing in the square. "John Paul was just wonderful, human, warm. [Benedict] is trying already."
Mauro Colombo, a Catholic living near Milan, found a warmth in Benedict's inaugural homily as well.
"This way of asking us to pray for him is very particular and touching," Colombo said.
After the Mass, Pope Benedict boarded his "popemobile," an open-topped, white sport utility vehicle that inched over the cobblestones in a 10-minute lap of St. Peter's Square, through a delighted crowd. The image was a trademark of Pope John Paul.
The Mass offered combinations of the old and new.
Pope Benedict's pallium, a ceremonial woolen scarf given to a bishop to signify his responsibility in shepherding a diocese and one of the church's most ancient pieces of raiment, was reshaped to more closely resemble the original style.
In an innovation, that symbol and other moments of the liturgy were explained to the crowd by narrators, in three languages, broadcast over the Vatican's sound and video system.