This grand altarpiece was commissioned by Pietro Martire Carli for the convent of Sant’Agnese in Bologna. It was started by Domenichino in Bologna and completed in Rome, where the artist moved in 1621.
The composition unfolds on two levels: earthly and celestial. In the upper register, bathed in light, the Trinity appears surrounded by angels playing musical instruments—an expression of Domenichino’s passion for music, as evident in the attention to detail.
Below, the martyrdom of Saint Agnes is depicted in the presence of women and soldiers. She is shown at the moment she is stabbed in the throat by order of Aspasius, prefect’s deputy, whose son she had rejected, having vowed her virginity to God. In the background, many figures witness the scene from a columned loggia.
The contrast between victim and executioner is striking: the latter drives the dagger into Agnes’s neck with one hand while gripping her long hair with the other. Saint Agnes, however, gazes ecstatically toward the heavens, already transcending the violence to receive the palm of martyrdom from Christ through an angel.
