Thousands Pack St. Peter's Square for Pope Francis' Inaugural Mass

Leaders from around the world fly to Rome for the historic event.

VATICAN CITY, March 19, 2013— -- Tens of thousands of people filled St. Peter's Square to welcome Pope Francis, the first Latin American pontiff, to celebrate his inaugural Mass in front of numerous heads of state from around the world.

Pope Francis rode around the square in an open-air jeep as he waved and kissed babies along the way. The pope exited the jeep at one point to bless a man who was in a wheelchair.

Speaking at his inaugural Mass, Francis reflected on Joseph, whom Catholics consider a saint, and his responsibilities in protecting Jesus and Mary, and said such responsibility extends to the pope himself.

"He is in touch with his surroundings," Francis said. "He can make truly wise decisions. In him, dear friends, we learn how to respond to God's call. Gladly and willingly.

"In his heart you see great tenderness. Which is not the virtue of the weak, but rather a sign of strength, of spirit and a capacity of concern for compassion, for genuine openess to others. For love, the capacity to love," he said.

Francis, dressed simply in the papal white cassock, arrived in St. Peter's Square earlier than expected. Upwards of 200,000 people jammed the square, according to Father Federico Lombardi, the director of the Holy See press office.

People began flooding into St. Peter's square at 6:30 a.m. local time, more than two hours before Pope Francis was schedule to arrive.

During the ceremony, Francis received the Ring of the Fisherman and the pallium, a special circular strip of cloth. Later, six cardinals approached the pope as an act of obedience to the new pontiff.

In past inaugural Masses, every cardinal in attendance professed his obedience, but Francis shortened that part of the ceremony.

Numerous heads of state from around the world are in attendance. Delegations from 132 countries are in Rome for the event, according to the Vatican.

The largest delegation, consisting of 19 people, comes from the pope's homeland of Argentina. The pope's fellow Argentine, President Cristina Kirchner, was in attendance. They have clashed in the past on social issues, but held a lunchtime meeting Monday.

Vice President Biden, who is Catholic, represented the United States at the event. He flew into town Sunday evening.

In recent days the new pope has earned rave reviews from church leaders and faithful alike, with one gesture of humility and informality after another.

The 76-year old Argentine's trademark style was first evident Wednesday when he was introduced to the world on the balcony overlooking St. Peter's Square wearing a simple wooden cross.

PHOTOS: Pope Francis Through the Years

In the days since, he decided to forego a ride in a limousine in favor of a mini-van, discarded the fancy red shoes of his predecessor Pope Emeritus Benedict XVI to don black shoes, and spontaneously greeted onlookers as he entered a mass at a small Vatican parish.

"How I would like a church that is poor and for the poor," Francis exclaimed at a Saturday audience with journalists.

In yet another gesture of modesty, Francis has urged his countrymen not to travel from Argentina for his inauguration, but rather to donate the money they would spend on the trip to the poor. After all, he is already pope -- the inaugural mass is simply a sacred celebration of his papacy.

Earlier Sunday, a whopping 300,000 people flocked to St. Peter's Square and the surrounding area for the pope's first Angelus, and even more are expected Tuesday. Security, of course, will be tight.

"There will be a lot of people, but I have no worries whatsoever about the way that they do security, the way that they provide protection. It is never in people's faces, never to drive people away," Vatican spokesman Father Thomas Rosica said. "They try to accommodate as many people as possible, always concerned for their safety."

Estimates in Rome about the possible attendance ranged up to 1 million people. For a pope who has proven exceedingly popular ever since his historic election last week, such a turnout would have been impressive, but not surprising.

"Rome has felt so empty since Pope Emeritus Benedict made his announcement and now it feels full again," said Jennifer Uebbing, an American now living in Rome, after Pope Francis' first Angelus Sunday. "He has a new grace and a fatherly way about him."

Click Here for a Profile of Pope Francis