First a little background. St. Agatha was a native of Catania, having lived between the years 231-251, so it should come as little surprise that the cathedral of Catania would be named after her and find important works of liturgical art within related to her. St. Agatha was subjected to torture and martyrdom at the tender age of 20 during the Decian persecutions. According to her legend, the Roman governor, Quintianus, had set eyes on St. Agatha -- who came from a wealthy family -- and wished to marry her, but Agatha had vowed her virginity to Christ. Hoping to sway her, he reported her for her Christian faith, hoping her arrest would give him the leverage to sway her but his plot failed. As a result, Quintianus had her imprisoned and tortured, racked, burned, beaten with rods and her breasts torn off. She was sent to prison where is it said she had a vision of St. Peter and would finally succumb to death.
But while her life had ended, St. Agatha would go on to become one of the most highly venerated martyrs of Christian antiquity, something that is testified to by the fact that her name is one of the few to be explicitly mentioned within the Roman Canon; devotion to her is also in evidence in Rome where there are two early basilicas dedicated in her honour, Sant'Agata de' Goti (founded in the fifth century) and Sant'Agata in Trastevere (founded in the eighth century).
Returning to Sicily, in 1726 the silversmith Saveiro Corallo would produce this exquisite, silver antependium which, as was noted earlier, graced the main altar of the cathedral.