Agatha is buried at the Badia di Sant'Agata, Catania.[c] She is listed in the late 6th-century Martyrologium Hieronymianum associated with Jerome, and the Synaxarion, the calendar of the church of Carthage, c. 530. Agatha also appears in one of the carmina of Venantius Fortunatus.
Two early churches were dedicated to her in Rome; Sant'Agata in via della Lugaretta, Trastevere, and notably the Church of Sant'Agata dei Goti in Via Mazzarino, a titular church with apse mosaics of c. 460 and traces of a fresco cycle,[d] overpainted by Gismondo Cerrini in 1630. In the 6th century AD, the church was adapted to Arianism, hence its name "Saint Agatha of Goths", and later reconsecrated by Gregory the Great, who confirmed her traditional sainthood.
Agatha is also depicted in the mosaics of Sant'Apollinare Nuovo in Ravenna, where she appears, richly dressed, in the procession of female martyrs along the north wall. Her image forms an initial 'I' in the Sacramentary of Gellone, which dates from the end of the 8th century.
Her written legend comprises "straightforward accounts of interrogation, torture, resistance, and triumph which constitute some of the earliest hagiographic literature", and are reflected in later recensions, the earliest surviving one being an illustrated late 10th-century passio bound into a composite volume[e] in the Bibliothèque nationale de France, originating probably in Autun, Burgundy; in its margin illustrations Magdalena Carrasco detected Carolingian or Late Antique iconographic traditions.
According to the 13th-century Golden Legend (III.15) by Jacobus de Voragine, 15 year-old Agatha, from a rich and noble family, made a vow of virginity and rejected the amorous advances of the Roman prefect Quintianus, who thought he could force her to turn away from her vow and marry him. His persistent proposals were consistently spurned by Agatha. This was during the persecutions of Decius, so Quintianus, knowing she was a Christian, reported her to the authorities. Quintianus himself was governor of the district.
Quintianus expected Agatha to give in to his demands when faced with torture and possible death, but Agatha simply reaffirmed her belief in God by praying: "Jesus Christ, Lord of all, you see my heart, you know my desires. Possess all that I am. I am your sheep: make me worthy to overcome the devil." To force her to change her mind, Quintianus sent Agatha to Aphrodisia, the keeper of a brothel, and had her imprisoned there; however, the punishment failed, with Agatha remaining a Christian.
Quintianus sent for Agatha again, arguing with her and threatening her, before finally having her imprisoned and tortured. She was stretched on a rack to be torn with iron hooks, burned with torches, and whipped. Amongst the tortures she underwent was the excision of her breasts with pincers. After further dramatic confrontations with Quintianus, represented in a sequence of dialogues in her passio that document her fortitude and steadfast devotion, Agatha was then sentenced to be burnt at the stake; however, an earthquake prevented this from happening, and she was instead sent to prison, where St. Peter the Apostle appeared to her and healed her wounds.
Agatha died in prison, probably in the year 251 according to the Legenda Aurea. Although the martyrdom of Agatha is authenticated, and her veneration as a saint had spread beyond her native place even in antiquity, there is no reliable information concerning the details of her death.