Januarius

Januarius ( JAN-yoo-AIR-ee-əs; Latin: Ianuarius; Neapolitan and Italian: Gennaro), also known as Januarius I of Benevento, was Bishop of Benevento and is a martyr and saint of the Catholic Church. While no contemporary sources on his life are preserved, later sources and legends say he died during the Great Persecution, which ended with Diocletian's retirement in 305.

Januarius is the patron saint of Naples, where the faithful gather three times a year in Naples Cathedral to witness the liquefaction of what is claimed to be a sample of his blood kept in a sealed ampoule.

Source: Wikipedia — https://en.wikipedia.org/wiki/Januarius