While the miracle occurs several times a year, the most celebrated occasion falls on September 19, the saint’s feast day and an annual public holiday in Naples (La Festa di San Gennaro).

The miracle of San Gennaro has its origins in the 4th century, when the saint was martyred in 305AD during the Great Persecution of the Christians under Emperor Diocletian.

At this time, San Gennaro was Bishop of Benevento, and was imprisoned while travelling to visit other captive Christians.

Legend has it that San Gennaro was beaten and tortured before being beheaded before a public audience.

Upon his murder, San Gennaro’s body and head were wrapped up and transported back to Naples, while women collected his blood with a cloth, which was later placed into two glass phials.

It’s said that as early as eight years after the saint’s death, the blood began to liquefy on certain occasions.

September 19 marks the most important day for the city of Naples, where locals flock to the Cathedral of Naples to see the saint’s blood liquefy.

A lively procession takes over the streets of Naples’ historical centre, Spaccanapoli, as the silver bust of San Genarro is carried to the Cathedral of Naples.

The saint’s silver bust is then placed by the altar in the Cathedral, and in an age-old ritual, the “zie” of San Gennaro (women seated in the first row of the Church) begin repeating a series of prayers to invoke the miracle.

It could take minutes, or t could take hours, but devout believers wait in anticipation and pray fervently for the blood in the phials to begin bubbling and turn into a liquid form in the hands of the resident Cardinal.

If the blood liquefies then the Cardinal announces “The miracle has happened”, signaling that the city is safe and days of festivities begin.

If the blood fails to liquefy, a different story unfolds.

According to traditional beliefs, if the miracle doesn’t occur, as has happened several times, then it is a bad omen for the city.

For example, the miracle of San Gennaro failed to occur in 1980, and was followed by an earthquake which took the lives of 2000 people.

Of course, this miracle is not without its skeptics, and many scientists and authorities have tried to disprove the legend of San Gennaro.

True or not, the miracle of San Gennaro is a fundamental part of Neapolitan culture and has great social and religious significance in the southern city and across the whole nation.

The miracle is even celebrated across Italian communities in other corners of the world, and Little Italy in New York City holds annual festivities in the saint’s honour.