The Four Crowned Martyrs are the patron saints of sculptors. St. Castorius, St. Claudius, St. Nicostratus, and St. Symphorian were tortured and executed in Pannonia, Hungary during the reign of Diocletian. According to legend, they were employed as carvers at Sirmium (Mitrovica, Yugoslavia) and impressed Diocletian with their art.
Diocletian commissioned them to do several carvings, which they did to his satisfaction, but they then refused to carve a statue of the Roman god Aesculapius, as they were Christians. The emperor accepted their beliefs, but when they refused to sacrifice to the gods, they were imprisoned.
When Diocletian’s officer Lampadius, who was trying to convince them to sacrifice to the gods, suddenly died, his relatives accused the Saints of his death. To placate the relatives, the emperor had them executed.
In the fourth and fifth centuries a basilica was erected and dedicated in honor of these martyrs on the Caelian Hill in Rome, probably in the general area where tradition located their execution. This became one of the titular churches of Rome, was restored several times.