VATICAN CITY - The body of Pope John Paul II, laid upon a red velvet bier, was carried Monday in a solemn procession from the Apostolic Palace in the Vatican, and presented to a reverent public in St. Peter's Square.

The procession of priests and cardinals, helmeted Swiss guards and candle-carrying monks snaked slowly through frescoed corridors and down marble staircases as a male choir chanted psalms and prayers in Latin. The body of the 84-year-old pope, who died two days ago in his bedroom in the palace, was held high by 12 white-gloved, black-suited men known as the pontifical chair-bearers.

As the bier entered the sunlight of St. Peter's Square, applause - a traditional Italian reaction to any momentous event - broke the silence. Just before entering St. Peter's Basilica, the pallbearers paused and turned the pope's body to face the crowd. Applause erupted again.

They lowered his body in front of the central altar, and shortly before 8 p.m., Vatican ushers opened the 16th-century basilica to tens of thousands of people who had filled St. Peter's Square, lined up on the broad boulevard leading to the Tiber River and flowed down a side street.

Many had waited more than eight hours to begin the slow approach to the basilica's doors. Vatican officials struggled to keep the line moving.

In order to ensure that as many visitors as possible can see the pope before he is buried, the basilica will be open around the clock except for 2 a.m. to 5 a.m., when it will be closed for what is described as "technical maintenance of the basilica," said Dr. Joaquín Navarro-Valls, the papal spokesman.

In addition to the historic ritual and public mourning, there was also serious decision-making.

Inside the palace, the cardinals assumed temporary control of the Roman Catholic Church and took an oath of secrecy about their deliberations. They scheduled the pope's funeral for Friday at 10 a.m. and made it clear that the pope would be buried here, according to tradition, rather than in his native Poland, as some had speculated.

The city of Rome began making elaborate preparations to receive millions of visitors for the ceremonies, including President Bush and other world leaders.

Reflecting the rich symbolism of the proceedings, Archbishop Piero Marini, the master of papal liturgical ceremonies, chose for the pope's final viewing red vestments that John Paul often wore in carrying out the Stations of the Cross, which represent Jesus' passion, Italian state television said.

A bishop's miter on his head, his feet turned outward awkwardly, the skin of his face chalky and drawn taut, the pope's body was placed in front of the central altar of the basilica. There, Cardinal Eduardo Martínez Somalo, the papal chamberlain, blessed him with holy water and incense and called the faithful to prayer.

"Oh Lord, our salvation, listen to us who are praying to you with all the saints," the cardinal said. "And welcome our pope, John Paul, who trusted in the prayer of the church, in Christ our Lord. Grant him eternal rest, our Lord. May perpetual light shine on him. May he rest in peace."

Sixty-five of the church's cardinals gathered in the Bologna Hall of the Apostolic Palace for the first meeting of the General Congregation of Cardinals since the pope's death on Saturday. They were led by the dean of cardinals, Cardinal Joseph Ratzinger, a German who is expected to play a leading role as a power broker during the conclave that will elect the pope.

They sat around a U-shaped table, with Cardinal Ratzinger at the center of its base, said a senior Vatican official attending the meetings.

Underscoring the mystery that will shroud most of their words and deeds, the cardinals took an oath of secrecy, as dictated by the constitution regulating papal transitions that John Paul wrote in 1996.

Immediately after the funeral, the pope will be buried in a crypt below the basilica, the popes' traditional place of burial.

"He did not state any wishes, and so we will follow tradition," Dr. Navarro-Valls said at a news briefing on Monday. In a sense, the public viewing began Sunday, when television cameras frequently broadcast live images of the pope's body as it lay in the Clementine Hall of the Apostolic Palace.

The cardinals' gathering was the first time so many had met since the pope's death, and scores more were expected to arrive in coming days.

It was not known whether the cardinals had set a date for the beginning of the conclave, when the 117 voting cardinals will gather in the Sistine Chapel to deliberate the future of the 1.1 billion-member church and choose one of their own as the next pope.

"It was really a business meeting with the cardinals," Cardinal Theodore E. McCarrick of Washington told CNN on Monday. "We got together and wanted to make sure that we're doing this in the way the holy father wanted us to, following his instructions and following the guidance that he gave us in that constitution."

He added: "Everything was done according to those outlines. And I think we were satisfied that we had followed the lead that he gave us and were faithful to what he had asked us to do."

The senior Vatican official said, "They were just as friendly and kind to each other as always."

Dr. Navarro-Valls said John Paul would "almost surely" be placed in the space that held the body of Pope John XXIII from his death in 1963 until 2000, when it was moved to the main floor of the basilica.

The city of Rome is gearing up for an estimated two million visitors. Train stations and stadiums for campers have been opened. Trucks of water have been transported to St. Peter's Square. Emergency vans and medical tents are on hand.

The police closed roads to all traffic except official cars and taxis in the immediate vicinity of St. Peter's Square. Posters mourning the pope's death were hung throughout the city. "A good man," read one of them.

Several airlines said their flights to Rome were sold out. The Polish airline LOT will be flying bigger planes and adding a special flight on Tuesday to accommodate Polish pilgrims, while the Polish rail company PKP will schedule special trains to Rome.

"This is a special time of mourning for the church," said Cardinal Roger Mahoney, archbishop of Los Angeles, said in an interview with CNN. "It's really almost as if we were pastors again making spiritual arrangements for all of the people."

The funeral also will bring together dozens of world leaders. Among those expected to attend are Mr. Bush and his wife, Laura; Prime Minister Tony Blair of Britain; President Jacques Chirac of France; Chancellor Gerhard Schröder of Germany; and President Bashar al-Assad of Syria.

Some cardinals seemed eager to talk about the electoral process.

Cardinal Philippe Barbarin, the archbishop of Lyon, France, told reporters there on Sunday that the next pope should have "a heart as big as the world," adding that questions about where he is from are secondary.

"What I demand of God is that whoever is elected is a real saint - someone in whom you can see the light of Christ, the power of the Gospel," Cardinal Barbarin said. He also said he already knew whom he would vote for, but did not disclose the name, adding, "Perhaps my brothers are going to make me change my mind."

Asked whether he could become pope, he joked, "They will not do such a stupid thing."

Other cardinals emphasized that they would enter the conclave undecided. "At this moment, I am puzzled about my future choice, because I have admiration for popes who have had totally different personalities," said Cardinal Henri Schwery, the only Swiss cardinal, in an interview published Monday in the Swiss newspaper Le Nouvelliste. But he added that he favored the election of a "pastoral bishop who has lived the real life of the grass-roots level."

In an interview on Saturday, Cardinal Achille Silvestrini, a former top Vatican diplomat, singled out the importance of creating a new "collegiality," between the new pope and the curial officials who run the Vatican itself on one side and clerics all around the world on the other.

Without criticizing Pope John Paul II, Cardinal Silvestrini, who at 82 is two years too old to vote, said a permanent, elected consultative body of bishops should be created in Rome as a bridge between the Roman Curia and the bishops. "More than divisions, there is a feeling of distance," he said. "The bishops feel a little far from what is happening in Rome."

The Vatican official who spoke anonymously disclosed new details about the immediate aftermath of the pope's death. He put to rest speculation that the pope's death had been confirmed by the centuries-old tradition of a tap to the forehead with a small silver hammer. "We have more modern ways," he said. "It would be an anachronism."

In a sign of the state of some of the church's business in the aftermath of the pope's death, a list of possible bishops was presented for his approval on Friday, the day before his death. He was unable to sign off on them. They will await his successor.