According to various sources, Januarius was born in Benevento to a rich patrician family near Naples, Italy. At a young age of 15, he became a priest of his parish in Benevento, which at the time was primarily pagan. When Januarius was 20, he became Bishop of Naples. During the persecution of Christians by the Emperor Diocletian in 305 AD, Januarius was arrested and beheaded at the Solfatara crater near Pozzuoli. According to the Roman Martyrology, “the body of St. Januarius was brought to Naples, and there honourably interred in the church, where his holy blood is kept unto this day in a phial of glass, which being set near his head becomes liquid and bubbles up as though it were fresh.”
The miracle of the liquification is the chief reason for the notoriety of St Januarius. The relic of blood is kept in a small flagon-shaped flask and resembles a dark and solid mass. On the Feast of St. Januarius (as well as at other times of the year) the reliquary is brought out and held by the celebrant in view of the assembly. Prayers are said by the people, begging that the miracle may take place. After a short period of time, the solid mass detaches itself from the sides of the glass reliquary and becomes liquid, sometimes even bubbling up. The celebrant then announces “the miracle has happened,“ and Te Deum (“We praise thee, O God”) is sung. Then the reliquary with the liquefied blood is brought to the altar rail so that the faithful may venerate it by kissing the vessel.
Although skeptical scientists have provided a number of explanations for the “liquification,” those explanations have primarily pointed to higher temperature “melting” the solid mass. However, for more than a century, careful observations of the temperature in the presence of the relic have been kept, and it has been demonstrated that there is no direct relation between the temperature, and the time and manner of the liquefaction. While the Catholic Church has always supported the celebrations, it has never formulated an official statement on the phenomenon, and maintains a neutral stance about scientific investigations. Whatever the cause, devotion to St. Januarius is very great in Naples. The blood has failed to liquefy several times, each time coinciding with the outbreak of disease, famine, war or political suppression. It is for this reason that Neapolitans rejoice at each liquification.