In the heart of Prato Cathedral, a precious belt of fine green wool, woven with gold threads, preserves a thousand-year-old bond between this city and its textile fortune. This relic, known as the Sacred Belt, has been the object of veneration and tradition since the late thirteenth century, when it was identified as the gift of the Virgin Mary to St. Thomas as she ascended to heaven.

History has it that this relic arrived in Prato around 1141 thanks to Michele Dagomari, a citizen who had made a pilgrimage to the Holy Land. There, he had married a young woman named Maria - who had brought the belt as a dowry - and Dagomari, dying in 1172, donated the belt to the Parish church of Santo Stefano, today the Cathedral of Prato.

The Sacred Belt has become the beating heart of Prato's religiosity and a precious heritage shared by the entire community. Its public display is regulated by the statutes of the Municipality, which - together with the Diocese - holds the keys necessary to extract it from its altar and reliquary. Over the centuries, the municipality has even demolished buildings to create a vast square in front of the church, a welcoming place for pilgrims.

In 1312, there was an attempted theft of the relic by Giovanni di Landetto, known as Musciattino, who was severely punished by having his hands amputated and sentenced to the stake on the Bisenzio river. This episode prompted an even safer placement for the belt, which was then placed in the Chapel of the Sacred Belt, completed in 1390. The interior of this chapel is decorated with frescoes depicting stories of the Virgin and the Belt, painted between 1392 and 1395 by Agnolo Gaddi and his assistants.

In 1434-38, artists such as Donatello and Michelozzo created the Pulpit outside the Cathedral, a place to display the Belt to the faithful gathered in the square during the Display.

Today, the Display of the Sacred Belt takes place five times a year, on the occasion of Christmas, Easter, 1st of May, 15th of August and, in a particularly solemn way, on 8th of September, the day of Mary's birth, coinciding with the celebrations of the Historical Parade.

Over the centuries, the Sacred Belt has received homage from princes, emperors, saints, bishops and popes. Its legendary history even tells of the presence of Saint Francis and his touching encounter with the relic. Pope John Paul II, during his visit to Prato on 19th March 1986, paid homage to this extraordinary relic, confirming its importance in the history and faith of this fascinating Tuscan city.