On the diptych’s left door, Mor portrays Alexander Farnese’s mother, who was Charles V’s illegitimate daughter by Juana van der Gheyst. Born in Audenarde in 1521, she died in Ortonna in 1586 after marrying twice in the emperor’s interest. Her first husband was Alexander of Medici, and after his death, she married Octavius Farnese, Duke of Parma. Following her second husband’s death, she was appointed Reagent of the Netherlands in 1559 by Philip II, who had recently returned to Spain to take the throne. In 1567, Margaret voluntarily resigned in disagreement with the Duke of Alba, who then took over her post.

Mor presents Margaret kneeling in a three-quarter view, turned to the right and holding a rosary. With his customary precision, he captures her energetic facial features, reddish hair, black dress and white ruff collar. Unlike the portrait of her daughter-in-law, Margaret of Parma does not look out at the viewer. Her appearance is thus much more reserved and distant that that of Mary of Portugal. The diptych’s right door presents Mary of Portugal at prayer. Born to King John III of Portugal’s brother, Duarte in Lisbon in December 1538, she married Alexander Farnese in 1565 and died in Parma in 1577. Therefore, this work must not have been painted before that wedding, and it is customarily dated after 1565. Mary kneels in front of a kneeler, turned to the left in a three-quarters view. She wears a copper-colored dress with gold-striped white sleeves, a ruff collar and double white cuffs. A rich, four-stranded chain hangs around her neck. While the small, rather than life-sized model used for this depiction is traditional in depictions of praying figures, the painter retains his customary approach, including his meticulous technique, the manner in which Mary turns her face toward the viewer, and her reserved expression, which is fitting for court portraits.

Silva Maroto, Pilar, Pintura flamenca de los siglos XV y XVI: guía, Madrid, Museo del Prado, Aldeasa, 2001, p.260-261