The painting represents the children of the English sovereigns Charles I of England and Henrietta Maria of France and was sent as a gift in 1635 to the Dukes of Savoy Vittorio Amedeo I and Cristina of France, to offer them an intense portrait of their three grandchildren. Little Mary, just four years old, takes center stage, while Carlo, the eldest son, turns his gaze to the viewer stroking the head of his dog, a beautiful setter spaniel, and three-year-old Giacomo Duke of York holds in his hands an apple, probably a symbol of fertility. The folds of the carpet, probably due to the continuous movements of the small models, betray their impatience to the long poses in front of the painter. The painter's ability appears extraordinary in rendering the physiognomies and precious clothing, the refinement of the laces and the iridescent reflections of the fabrics, which connotes him as the most important portraitist of the seventeenth century at the European courts and aristocratic families.