The two saints kneeling in the foreground are the little-known St. John of Matha, a native of Faucon in Provence, and St. Felix of Valois, who lived at the turn of the twelfth century. Both were founder members of the Order of the Trinitarians, whose main mission was to free captives taken by the Moors, either by offering ransoms or themselves, by proxy, hence their role as patron saints of prisoners. St. John holds a devil at his feet leashed to a chain, while St. Felix proffers his shackles to the Virgin and Child. The drawing was presumably made as the design for an altarpiece, though no such work has so far come to light.

The drawing´s handling and its rudimentary compositional treatment point to Calvaert´s mature period, around 1580. A similar design is found in the artist´s altarpiece of The Virgin Appearing to Sts. Francis and Dominic in the Gemaldegalerie, Dresden, dated 1598. Here also two saints kneel on the ground, with the Virgin and Child in the middle of the sky above. In the Dresden picture, however, St. Francis is positioned slightly in front of St. Dominic, and is consequentially marginally larger in size. In the Prado drawing, however, the two saints are directly opposite each other in the same plane. Only the gesture of their arms in rhythmical counterpoint to each other suggests movement-not into depth but upwards, complimenting the ring of clouds encircling the Virgin and Child.

Seen here are echoes of the Flemish tradition of drawing, not only in the metallic, blue washed ground and lavish white heightening, but also in the sparing angularity of the pen contour. Many compositional studies by Goltzius are done on such colored preparations, with a similarly taut pen line limited to defining only essentials (Text drawn from Turner, N.: From Michelangelo to Annibale Carracci. A century of Italian drawings from the Prado, Art Services International-Museo Nacional del Prado, 2008, p. 136).