In the spirit of the Eucharistic Miracles series, I present the story of San Gennaro - Saint Januarius, Bishop and Patron Saint of Naples. This miracle is not one of the Eucharist, but is worth looking into.
Miracle of San Gennaro's blood - which liquefies from solid clots to blood up to two times per year. In 305ad San Gennaro was decapitated by the Romans. Some of his blood was preserved in a glass vile which is kept in the Naples Cathedral, Duomo di San Gennaro. This miracle happens nearly every September 19th, on his feast day. On years when it does not happen, Naples is said to be without the protection of their patron saint. In 1980 the blood did not liquefy and there was an earthquake which killed 2000 people.
To read more, check here:
It is said, before he was beheaded that Diocletian had him thrown into the stadium with wild bears which had not been fed in days - yet the bears paid no attention to San Gennaro. Diocletian then had him cast into a fiery furnace - and he came out of it unscathed. Being frustrated by these two attempts, he finally had the Bishop of Naples beheaded.