The famous basilica of San Giovanni Battista, the Chapel of Theodolinda, the specially made altar, the safe, the safety case, one after the other, they protect and jealously guard the most important and meaningful work of goldsmithery in all the history of the West: the Iron Crown.
An ancient tradition, already reported by Saint Ambrose at the end of the fourth century, identifies the metal circle that is seen inside the Crown and that gives it the term “iron”, with one of the nails used for the crucifixion of Christ.
The relic was found during a trip to Palestine in 326 by Saint Helena, mother of Emperor Constantine, and placed in the forged diadem for her son.
The relationship between the Iron Crown and Monza becomes so indissoluble that in 1354 Pope Innocent VI established that the Cathedral hosted the coronations of the kings of Italy and in 1576 San Carlo Borromeo established the cult of the Sacred Nail, to unite the Crown with the other Sacred Nail preserved in the Duomo of Milan.
The story that links the Crown to the Passion of Christ and to the first Christian emperor, explains the high symbolic value attributed by the kings of Italy (or by aspirants such as the Visconti), that they would use it in coronations to attest the divine origin of their power and their link with Roman emperors.
