Pope Francis installation: Inside the pageantry

(CBS News) Hundreds of thousands packed St. Peter's Square on Tuesday. This time, they watched the inaugural mass, formally installing Pope Francis. He is now officially the 266th leader of the Roman Catholic Church.

Papal inaugurations used to be known as "enthronements." The service has been much simplified, but still carries the weight of centuries of ritual and tradition.

Francis' tour of the crowd in his Popemobile through a sea of flags from dozens of nations was a modern version of the "triumph" ancient Romans held to reward conquering heroes.

Pope Francis officially begins his ministry
Special section: Change at the Vatican

But in keeping with the new style he is setting for the papacy, Francis connected with the adoring crowd, rather than lording over them, stopping his open Popemobile to kiss babies -- even getting out to bless a disabled man.

The service is known as the "Beginning of the Petrine Ministry of the Bishop of Rome," a reference to St. Peter, and Francis prayed in front of his tomb before the mass began to a hymn celebrating Christ and innumerable saints. Two major symbols of the papacy were presented: the pallium, a woolen stole representing a lamb being carried on a shepherd's shoulder; followed by the Ring of the Fisherman -- so named because Peter, a fisherman by trade, was instructed by Christ to be a "fisher of men."

By contrast, none of the dignitaries who ranged from royalty to heads of state, U.S. Vice President Joe Biden and various prime ministers and diplomats, were actually personally invited. For the first time in almost 1,000 years, the patriarch of the Orthodox Church chose to come.

And Francis had a simple message: protection and hope. Invoking the saint from whom he took his name, Francis called for respect for people and the environment. "In the end everything is entrusted to our protection," he said, "and all of us are responsible for it."

The crowd wasn't as huge as predicted, but there was no doubting the enthusiasm. Karen Reis, visiting from St. Louis, said, "I'm so excited, I feel so blessed. I can't believe I'm here still."

And in another example of simplicity, the pope didn't give anyone in the crowd communion, but 500 priests did.

An unmentioned feature of this ceremony is that many of the dignitaries, including Biden and former House Speaker Nancy Pelosi are pro-choice and support same-sex marriage -- a stark contrast to the conservative pope. Nonetheless, he's greeting all the dignitaries and it's doubtful that those issues will be raised during meetings with the new pope.