Waving palm fronds and olive branches - symbols of peace - pilgrims, tourists and Romans packed St. Peter's Square on a sunny, breezy day for the start of Holy Week ceremonies. When the ceremony began, the square was nearly full, but by its end, a crowd numbering in the tens of thousands spilled over into the broad boulevard which leads to the Tiber.
Palm Sunday's liturgy recalls Jesus' triumphal entry into Jerusalem, and Benedict's homily reflected on how the triumphs of men and women are also tempered by selfishness and evil.
"From the beginning, men and women have been filled - and this is as true today as ever - with a desire to be like God, to attain the heights of God by their own powers," the pope said. "All the inventions of the human spirit are ultimately an effort to gain wings," he added.
"Mankind has managed to accomplish so many things: we can fly! We can see, hear and speak to one another from the farthest ends of the earth," the pope told the faithful.
"And yet the force of gravity which draws us down is powerful," dragging people "toward selfishness, falsehood and evil," the pope said.
He also referred to recent natural disasters that man has been unable to control, noting that "our limitations have also remained."
Near the ceremony's beginning, Benedict, wearing crimson-and-gold colored robes, silently observed a long and solemn procession of prelates and rank-and-file faithful as a choir's voices rang out across the square, and he blessed the palms and olive branches. Clerics sang a nearly hourlong recounting from the Gospels of the events which led to Jesus' suffering and crucifixion.
Benedict turned 84 on Saturday. As the ceremony ended, a man in the crowd shouted: "Long live the pope" and some faithful broke into a the Italian version of "Happy Birthday To You."
The pope's stamina appeared to hold up well during the nearly three-hour appearance, the first of a series of public ceremonies as Holy Week continues.
The services include a feet-washing ceremony on Holy Thursday and the traditional nighttime Way of the Cross procession at the Colosseum on Good Friday. Tens of thousands of faithful are also expected for Easter Sunday Mass.
Even bigger crowds are expected May 1, when Benedict will beatify his predecessor Pope John Paul II in St. Peter's Square.