This miniature was originally included in an antiphonary volume illuminated by Sano di Pietro for the Hospital of Santa Maria della Scala in Siena. The scene inside the initial D illustrates one of the responses for the Feast of Saint Agatha (February 5): "Dum torqueretur beata Agatha in mamilla graviter dixit ad iudicem impie crudelis et dire tyranne" (While blessed Agatha was being cruelly tortured in her breasts, she said to the judge: godless, cruel, infamous tyrant). The initial portrays the martyrdom of Saint Agatha, whose torture and execution were ordered by the Roman consul Quintianus, enthroned at right, after she refused his advances. The beautifully appointed interior, graceful figures, and luminous palette contrast markedly with the gruesome subject.
The Hospital choirbooks, written and decorated between 1456 and 1476/77, represent one of the largest and most prestigious manuscript commissions in fifteenth-century Siena. Sano di Pietro, who by the mid-fifteenth century was one of the principal painters and illuminators in Siena, was entrusted with the decoration of at least five of the twenty volumes in the series. The Lehman Saint Agatha is one of many initials and full leaves painted by his hand that were removed from these books and sold to collectors sometime during the nineteenth century, before transfer of the choirbooks to the Museo dell'Opera del Duomo.