The painting is a double portrait of Archduchess Maria Maddalena of Austria and her son, Ferdinand, the future Ferdinando II de' Medici, Grand Duke of Tuscany.
Completed around 1623, after the death of Ferdinand's father, Cosimo II de' Medici, Grand Duke of Tuscany, the painting shows Maria Maddalena in the center, with her right hand next to Cosimo II's crown and her left hand resting on her young son's shoulder.
[1] It is believed that the first work he completed for the Medici was the 1622 portrait of Cosimo's widow, Marie Madeline, who became Susterman's first patron[1] In her hair at the top right she is carrying the Florentine Diamond.
[1] By showing the Grand Duke's crown, Sustermans symbolically included Cosimo II in the portrait of his wife and son.
[1] By the time the portrait was completed, Marie Madeline was co-regent of the Grand Duchy, along with her mother-in-law Christina of Lorraine.