The blood of St. Januarius liquefied on May 2, Cardinal Crescenzio Sepe of Naples announced joyfully to his people as he blessed the city with the relic. St. Januarius, who was martyred during the persecutions of Diocletian, is the patron saint of Naples. A vial of his blood, preserved by the faithful since the 4th century, regularly turns into liquid form on his feast day and sometimes on certain other days, including the first Saturday in May. Many residents of Naples believe that if the saint’s blood does not turn to liquid form, it is a sign that some tragedy will befall the city.