May the 6th used to be the Feast Day of the Martyrdom of Saint John before the Latin Gate (Porta Latina) in Rome, until 1960. The Golden Legend and the Roman Martyrology, as well, tell us the narrative of this martyrdom. The Roman Emperor Domitian tried to execute St. John, old man at that time, at the Latin Gate, where the martyrdom is traditionally said to have occurred, by having him put into a cauldron of boiling oil. The Apostle was left unharmed, and then was banished into the little island of Patmos in Greece. In the place of the martyrdom the Basilica of St. John at the Latin Gate (San Giovanni a Porta Latina) was erected.
Donatello, 1428-1443, Martyrdom of Saint John before the Latin Gate, Basilica di San Lorenzo, Florence.
Filippino Lippi, 1487-1502, Torture of St John the Evangelist, Cappella di Filippo Strozzi, Basilica di Santa Maria Novella, Florence.