To pass through the walls protecting Siena, Italy, from the outside world is to pass through a time warp — one that brings you straight back to medieval times.

The people are contemporary enough, but the static visual cues send a different message to the brain. Along ancient streets and in front of deeply weathered buildings, open-air markets sell their wares. Strung overhead from rough twine, fresh garlic cloves and wickered Chianti bottles bob in the breeze. It's clear the city's infrastructure has changed little since it was first erected.

The day I walked into the walled city, I could sense the excitement building around me as fellow pilgrims looked for the black-and-white striped tower of the famed Duomo of Santa Maria dell'Assunta. Others wondered aloud how to find the incorrupt head of St. Catherine of Siena. (It's in St. Dominic's Church.) But for me, it was the Basilica of St. Francis that beckoned most urgently.

The basilica stands in striking contrast to the duomo (cathedral). Where the duomo and its square are constantly crowded, the basilica is practically empty much of the time. This is especially noticeable because the basilica is so massive in size. I walked in to find myself one of just two other pilgrims and one friar, the latter sitting by the Blessed Sacrament.

One of the first things I noticed was how the sunshine streaming in through the stained-glass windows bathed the lateral side chapels winging the main altar in colors. I knew instantly that, once I settled in, I would not want to leave.

Soon the sounds of Benediction in a chapel opposite the main altar, to the right, drew me there. Bells rang, people gathered and an organist played a hymn of Eucharistic adoration. The Italians sang heartily as the priest raised an elaborate monstrance displaying the Blessed Sacrament.

Miracle Particles

On Aug. 14, 1730, the people of Siena gathered in the duomo for the Assumption Mass, leaving the basilica deserted. The next morning, during Mass in the basilica, the priest realized the lock of the basil-ica's tabernacle had been picked — and the ciborium was gone. Later that day, someone found the ciborium's lid in the street. Immediately the theft was considered a sacrilege. Aghast, the townsfolk canceled the Assumption festival. The archbishop ordered reparation prayers in public. Police searched for the stolen hosts.

Two days later, on the morning of Aug. 17, a cleric noticed something white protruding from a poor box in St. Mary's Church of Provenzano. The poor box usually went unnoticed because it was only cleaned once a year. The head friar sent for the archbishop, who dispatched someone to help the friars open the box. They discovered a great many hosts inside, some even hanging from cobwebs. The hosts were terribly dirty and covered with dust.

The priests cleaned them gently and examined them alongside unconsecrated hosts from St. Francis. Those found had the same shape and marking. They amounted to the same number that had gone missing: 348 whole hosts and six halves. A miracle!

The archbishop returned the hosts to St. Francis the next day, leading the people in procession along the specially decorated streets of Siena. The sacred particles were carried under a canopy preceded by scores of torches and pendants.

The news spread through the country quickly, and groups began arriving to pray before the hosts. Instead of being given out in Communion or consumed by a priest at Mass, they were kept for veneration. The friars decided to let them deteriorate according to natural processes and, of course, God's will. As long as they remained, the Real Presence of Christ remained.

Yet the hosts never did deteriorate. In fact, even after 50 years, they had a pleasing aroma. On April 14, 1780, Father Carlo Vipera, the Conventual Franciscan minister-general, tasted a host. It was still fresh. Though the original decision had been to not distribute them as Communion, some had been, reducing their number to 230. After recounting, Father Vipera placed the hosts in a different ciborium and forbade their distribution.

Nine years later, the archbishop opened another investigation with a group of dignitaries and theologians. They examined the hosts through a microscope — and found them completely intact. During their questioning by the archbishop, three friars from the 1780 investigation took an oath declaring these hosts were indeed those stolen in 1730.

As an experiment, the archbishop sealed some unconsecrated hosts in a box and kept it safely in the chancery for 10 years. After that period, he reopened the box. Sure enough, the hosts had greatly deteriorated. This ruled out the possibility of some atmospheric anomaly accounting for the supernatural preservation.

In 1914, a group of theologians, scientists and scholars formed a special commission at the request of Siena's archbishop — acting under the authority of Pope St. Pius X — to conduct a highly scientific investigation. University of Siena professor Siro Grimaldi wrote a book on this experience, A Scientific Adorer. An acid and starch test on one host fragment indicated a normal starch content for all the sacred particles. After more testing came the verdict: The hosts had been made of roughly sifted wheat flour, which was found to be well preserved.

The commission stated that, based on its analysis, unleavened bread made in sterile conditions and kept in airtight containers could be preserved for a long while. But unleavened bread made and kept in ordinary conditions would not keep for more than four or five years. The 1730 hosts had been made and kept under ordinary conditions.

Sacred Siena

In 1950, the sacred particles were placed in an ornate receptacle after being examined by experts and officials. The results equaled other examinations, but some of the hosts crumbled due to the tasting. The remaining number was 223.

Perhaps inspired by the original mischief-makers, another thief stole the precious container on Aug. 5, 1951. He tossed the hosts out near the tabernacle. This time, after cleaning them, the archbishop sealed the hosts in a silver ciborium. On June 10, 1952, the sacred particles were recounted before witnesses and photographed. A new monstrance was made.

Through the years, many saints and other holy souls have prayed before Siena's sacred particles. The miracle played a part in the conversion of Danish Lutheran writer Johannes Joergensen, who called them one of the greatest miracles on earth. Other visitors included St. John Bosco, Blessed Savina Petrelli, Giovanni Montini (who later became Pope Paul VI) and Angela Maria Roncalli (who became Blessed Pope John XXIII). Popes Pius X, Benedict XV and Pius XI all recognized the miracle, although they never visited the basilica.

Perhaps the most renowned pilgrim was Pope John Paul II. On Sept. 14, 1980, the priceless monstrance was brought to the duomo, where the Holy Father knelt before the hosts. His only words summed up the miracle: “This is the Presence!”

As my own visit concluded, the priest blessed us with the sacred particles. I reflected how much the world has changed since 1980, let alone 1730 — yet how unchanging is Jesus’ Eucharistic Presence in this walled medieval town.

Mary Soltis writes from Parma, Ohio.