Bia de’ Medici was born in 1536 as the first child of the Cosimo I, Grand Duke of Tuscany. She was known as Bia which could be the short version of Bianca or “la bambina.” The identity of her mother is not clear. Cosimo I and Maria Salviati (his mother) were the only people knew her identity who refused to reveal it. Though, both of them admitted her as the daughter of Cosimo. During her short life, she was deeply loved by her father and grandmother, also probably by her stepmother (Elenora of Toledo).
Bia grew up in a nursery at the Villa di Castello under the care of her paternal grandmother Maria Salviati Medici. She shared nursery with Guilia de’ Medici, the illegitimate daughter of Alessandro de’ Medici until her half-siblings arrived. Bia grew up as a lovely and lively girl at the nursery. Cosimo, who was known for his fondness of his daughters, adored his firstborn daughter. Also, Maria Salviati described her as a very tender child and comfort of the court.
Unfortunately, in February 1542, both Bia and Giulia contracted a fast-moving fever. Giulia recovered but Bia did not. Cosimo was receiving daily reports about her condition. But she got weaker after 25 February and died on 1 March. Bianca was buried in the Medici Chapel in San Lorenzo.
Cosimo I was devastated by his loss. He found some joy after six months, with the birth of another daughter. Surprisingly, the new daughter Isabella was very similar to Bianca. Both shared a graceful beauty with reddish blonde hair and brown eyes. Sadly, also Isabella could not have a long and joyful life as she was murdered by her husband.
In contrary to her short life, Bianca became immortal with the painting of Agnolo Bronzino, which commissioned by Cosimo I after her death. On the painting, Bia wears a medallion with her father’s profile to emphasize her link to the family, like every admitted illegitimate de’ Medici child. Also, she wears pearls on the portrait which were often worn by legitimate female members of the family, probably to emphasize the importance of the Bianca. Moreover, even though it was not an official portrait, it stayed in the private family rooms as a reminder of the beloved child.
Currently, the portrait is exhibited in the Galleria degli Uffizi in Florence as one of the most famous works of Bronzino and continues to inspire modern artists.