The "one-block-at-a-time" strategy was to help avoid a chaotic rush and crush of tens of thousands of people when the square opened at 5:30 a.m.

An estimated 800,000 people were on the streets of Rome April 27 to see two popes, Pope Francis and retired Pope Benedict XVI, concelebrate the Mass honoring the canonization of two of their predecessors, Sts. John Paul II and John XXIII.

The square was packed to capacity as more than 500,000 people filled the surrounding area; those unable to cross the bridges to the Vatican watched from large screens in several areas throughout the city, including the Roman Forum and Piazza Navona.

The red and white flags of Poland dominated the square and streets leading to the basilica while the gray, overcast sky saw splashes of color with enormous yellow and white balloons held aloft.

"Slowly! Slowly!" volunteers and police shouted at people who starting running for any kind of opening ahead of them that might get them closer to the square and the chance to catch a glimpse of the ceremony.

Almost 3,000 journalists were officially accredited for the event to provide coverage around the world.

Julia Desilets was one of the people carrying a candle alongside the relic of St. John Paul. Desilets, from western Massachusetts, had been working as a translator in the office promoting his sainthood cause.

She told Catholic News Service she was "amazed and extremely honored" to participate in the canonization Mass. "It was an appropriate ending, I believe, to my long sojourn here in the Eternal City."

About 150 cardinals and 700 bishops concelebrated the Mass. About 6,000 priests attended, as well as deacons, to help distribute Communion to as many people as possible.

U.S. Deacon William Ditewig of the Diocese of Monterey, Calif., specifically asked Vatican organizers to place him as far away from the main square as possible.

Deacon Ditewig told CNS he was inspired by Pope Francis' call to minister to the "peripheries," and "I wanted to minister literally to the fringes.

"These people went to all this trouble to be here, I wanted to distribute Communion as far away as possible" and help everyone feel a part of the ceremony.

He said he hoped to inspire those who might be disappointed with being so far away from the main event "with my demeanor of joy. This is a pilgrimage, not a tour, so I hope through demeanor and action," he could uphold the ideals of celebration, sacrifice and humility.

In order to get into the square on Divine Mercy Sunday, many people stayed up all night or attempted sleep on makeshift beds of flattened cardboard boxes or sleeping mats.

Many found shelter in churches and squares or along the roads leading to the main boulevard that leads to St. Peter's Square. A large group of French Scouts set up camp outside the French Embassy in Piazza Farnese and were trying to get some sleep around midnight.

In the center of Rome, pilgrims began an all-night vigil April 26. Large pockets of reverence existed side-by-side the wild revelry of a Saturday night in Rome. As Roman restaurants and bars were filled with winers and diners, the city's squares and streets were flowing with large groups of pilgrims carrying rosaries, backpacks and flags.

All of Piazza Navona was turned into an open-air church for Polish pilgrims. An altar was brought outside to the front steps of the church of St. Agnese in Agone to allow hundreds of people the opportunity to kneel and pray before the Blessed Sacrament.

About a dozen churches were open all night for eucharistic adoration, confessions and prayer services in seven different languages.

Starting at about 7 p.m. April 26, security officials closed off St. Peter's Square, gently ushering people outside the metal barricades and directing them toward the main boulevard of Via della Conciliazione, which was completely sealed off to incoming car and pedestrian traffic.

The several thousand people who refused to vacate the boulevard were allowed to spend the night. People unrolled sleeping bags, unpacked blankets and mylar wraps, and set up folding chairs or lay down cardboard for beds.

Several engineering students from Milan could not believe their good luck in being on the boulevard just several hundred yards from the square.

"We're here to give thanks and ask for prayers for our studies, our families and our future -- to understand who we are," said Matteo Braida, 24, who came with his friends Marco Camillini, 21, and Luca Costantini, 22.

When asked, "Where is John?" seeing the three friends had the Italian versions of the names Matthew, Mark and Luke, Luca replied, "John's not here, but we have Letizia," his girlfriend.

The three friends had been to Rome for the 2011 beatification of St. John Paul, but only Braida had managed to get into the square.

He said it was worth the sacrifice and trouble because "you feel it more, the experience is better. If you make the effort to come to Rome, that's a lot, but if you have to watch from a big screen, you might as well be at home."

Two women from Ireland's County Mayo, Eileen O' Grady of Louisburgh and Teresa Lawless of Westport, managed to claim a travertine marble bench along the boulevard.

They had been to Rome for at least five other beatification and canonization ceremonies, and they were prepared for any kind of weather, wearing pastel rain ponchos, gloves and straw sunhats in the dark, damp night.

Lawless said they planned to do what they usually did on large pilgrimages: stay up all night reciting the rosary.

"When you pray, time just goes like that," she said with a finger snap.

Leading a group of 30 American pilgrims was Lino Rulli, "The Catholic Guy" talk-show host whose show airs on the satellite radio Catholic Channel.

Rulli, who has brought several pilgrimage groups to Rome over the years, said he gave the people on his tour advice for how to get as close as possible to the square.

"Try to get behind the Germans. They have a history of sacking Rome and invading" the square, he said, referring to the several first-century invasions and the infamous Sack of Rome in 1527.

On a more serious note, he said the huge turnout was a great sign that "so many people want to go to church, that people are willing to wait 12 hours to go to Mass."

It's almost like "the harder you make things for people, the more they are drawn to religion," he said.