Cardinals bow to remains of Pope John Paul II resting in wooden casket during funeral Mass in St. Peter's Square at the Vatican, Friday

Presidents, patriarchs, prelates and pilgrims said goodbye Friday to Pope John Paul II during an emotional funeral service in Saint Peter's Square. As many as four million people flocked into Rome to attend the funeral, or watch it on giant television screens placed around the city.

As befits a 2,000-year-old church that has mastered the art of pageantry, the funeral was a solemn occasion, meant to honor a man whom political and religious leaders have described as a giant of his era.

The dean of the Roman Catholic Church's College of Cardinals, Joseph Ratzinger, presided over the funeral mass. The normally stern prelate choked with emotion as he recalled John Paul's appearance at the window of his apartment only 12 days ago, on Easter Sunday, when he blessed the faithful in the square below.

Cardinal Joseph Ratzinger, center, blesses coffin containing body of Pope John Paul II, during funeral mass in St. Peter's Square at the Vatican, Friday

"We can be sure that our beloved pope is now at the window of the house of his father, and he sees us, and he blesses us," said Cardinal Ratzinger.

Cardinal Ratzinger's homily, or sermon, was interrupted several times by applause from the faithful, a sign of respect in Italy. But toward the end of the Mass, a loud chant arose from the 300,000 people gathered in the square and on the wide boulevard leading into it, demanding that John Paul II be canonized immediately.

The spontaneity of the crowd contrasted with the ritual of the funeral, but everyone joined in to intone the litany, in which the church calls on its many saints to pray for the soul of the departed.

People wave Polish, Mexican, French and Spanish flags during the funeral mass for Pope John Paul II

Many of the pilgrims in the square were from Poland, coming to say goodbye to the man they regard as a father figure and national hero. The pope is given credit for helping to bring down the Iron Curtain. But he is also recognized as having built bridges to other religions.

There were Jews and Muslims and Orthodox Christians among the religious dignitaries attending the funeral. And, patriarchs of the eastern rite churches, which are in communion with Roman Catholicism, chanted in Greek as they waved incense burners over the pontiff's simple wooden coffin.

Pope John Paul II's coffin is lowered into the grave inside the grottos beneath St. Peter's Basilica

As John Paul's coffin was carried inside the basilica for immediate burial in the papal crypt, bells rang out in the vicinity of Saint Peter's as a final farewell for a pope with whom many Catholics disagreed, but whom most adored.

The next time those bells ring will be when the cardinals of the church choose a successor to John Paul II. They are scheduled to begin their conclave, as the closed-door meeting is called, on April 18.