Worshippers, civic dignitaries, scholars and tourists meet together in the Duomo in Naples every year on 19 September to remember the martyrdom of the patron saint of the city, San Gennaro.
Every year a service is held during which the dried blood of the saint, which is kept in glass phials in the Duomo, turns to liquid.
The practice of gathering blood for relics was a common practice at the time of the decapitation of San Gennaro in 305 and the ritual of praying for the miracle of liquefaction dates back to the 13th century in Naples.
The festival of the saint’s martyrdom is celebrated by Neapolitan communities all over the world and the recurrence of the miracle each year is televised and reported in the newspapers.
On the few occasions that the miracle hasn’t happened, Neapolitains have dreaded a catastrophe occurring. In 1980 after the liquefaction failed to take place a massive earthquake struck the region.