Should you happen to be in Naples on this date, or on December 16, or on the Saturday before the first Sunday in May, make it your business to drop in on the cathedral where you may be fortunate enough to see a miracle. At these times, the dried blood of St Januarius (or San Gennaro to the locals) will liquefy.
Januarius was the bishop of Naples during the time of the persecution of Christianity by the Emperor Diocletian at the beginning of the fourth century. In 304, he was thrown to the bears and then beheaded. His relics were preserved and it was noted in 1389 that when the ampoule containing his blood was brought near the reliquary containing his head, liquefaction occurred. This miracle came to occur regularly on his saint’s day (today), the anniversary of the translation of his relics, and on the festival of his patronage of Naples.
On March 21, 2015, the blood in the vial appeared to liquify during a visit by Pope Francis. This was taken as a sign of the saint’s favour of the pope. The blood did not liquify when Popes John Paul II and Benedict XVI visited nor when Naples elected a Communist mayor. Make of that what you will.
Januarius is the patron of Naples and blood banks and may be invoked against volcanic eruptions.