A dramatic Baroque oil painting by Guercino, depicting the biblical liberation of Saint Peter by an angel in a dark prison cell.

Guercino, born Giovanni Francesco Barbieri, painted this work in 1622 during his time in Rome. The composition depicts the biblical account from the Acts of the Apostles, where an angel awakens Saint Peter in his prison cell to facilitate his escape. The artist employs a dramatic use of light and shadow, a technique known as chiaroscuro, to define the figures against the darkness of the dungeon.

The angel, positioned on the left, gestures towards the exit, while the aged Saint Peter appears dazed and disoriented by the sudden intervention. To the right, a guard remains fast asleep, oblivious to the miraculous event occurring mere feet away. The contrast between the ethereal, illuminated form of the angel and the heavy, slumbering figure of the guard creates a tension that defines the narrative. Guercino focuses on the physical reality of the scene, from the texture of the chains to the weary expression on the saint's face.

This painting demonstrates the artist's ability to manage complex lighting effects to guide the viewer's eye. The palette is restrained, relying on deep ochres, blues, and warm flesh tones to maintain the somber atmosphere of the prison. The work remains a clear example of the Bolognese school's approach to religious subject matter during the early seventeenth century, prioritising emotional clarity and naturalistic detail over excessive ornamentation.