Art historians believe the portrait may have been intended as a gift for his mistress, Taddea Malaspina, the sister of the marchioness of Massa, to commemorate the birth of their second child, Giulia.

Maria Salviati, the mother of Cosimo I, supervised the nurseries and watched over Giulia's bedside anxiously when the little girl became ill in February 1542.

Giulia survived the fever, but her companion in the nursery, Cosimo I's illegitimate daughter Bia de' Medici, died.

[3] As she grew up, Giulia was completely integrated into life at court and was educated to a high standard, as were the daughters and other female wards of Cosimo I.

When she was twelve or thirteen, Cosimo I's wife Eleonora of Toledo was outraged because Giulia's riding cloak did not look right; it was not decorated as she had ordered and it was the wrong length.

Cosimo arranged an advantageous marriage for her with Francesco Cantelmo, the Duke of Popoli, in 1550, when she was about fifteen years old, and provided a dowry for her of an amount that would be worth about eight million United States dollars today.

Art historian Gabrielle Langdon argues that the girl's demeanor in the portrait is different than would have been expected for the child Cosimo, whose family anticipated his role as a strong leader from his earliest days.

Mario de Valdes y Cocom, a historian of the African diaspora, argues that the sloping arm of the chair also represents Monte della Verna, which Saint Bonaventure, a Christian scholastic theologian and philosopher, visited and where he was inspired to write his Itinerarium mentis in Deum.

Some modern scholars see the painting as Giulia's response to criticism of her grandmother's north African descent and marriage to the mule driver from Collevecchio.

[4] Sometime in the 1560s, her relationship with her former guardian may have cooled when Giulia insisted that she be treated as an equal to Cosimo I's mistress, who was regarded with general disdain at court.