St Januarius, or San Gennaro, was martyred during the persecutions of Diocletian around 305 CE. It is believed that Januarius was born in Benevento, northeast of Naples, in the 3rd century CE. He became the local priest of his parish at 15, and then was appointed as the Bishop of Naples at 20. St Januarius is believed to have died while visiting Christians imprisoned in Rome
Many devoted Catholics travel to the Doumo (cathedral) of Naples on September 19, where it is believed that the patron saint’s blood liquefies. People also travel to the cathedral to witness this “miracle of the blood” on December 16 and on the Saturday before the first Sunday of May.