She died in Florence at just 23, leaving behind a legend that has survived more than five centuries. Simonetta Vespucci, the woman identified with the ultimate Renaissance ideal of beauty, has been linked more than anyone else to the figure of Venus in Sandro Botticelli’s famous painting.
Known as the “Bella Simonetta,” she died in April 1476. For nearly five and a half centuries, the exact cause of her early death remained unclear. The prevailing historical account attributed it to tuberculosis or, according to other reports, pneumonia.
A new study published in June 2026 in the scientific journal Endocrinology, Diabetes & Metabolism offers a different explanation. Simonetta may have died from pituitary tumor apoplexy, a rare but extremely dangerous condition in which an existing tumor suddenly bleeds or swells.
The researchers stop short of a definitive diagnosis, since that would be impossible without medical or anatomical evidence, and instead describe it as a retrospective medical hypothesis. For the study, they connected historical accounts of Simonetta’s final days with features they believe can be seen in portraits that have, at various times, been identified as her.
Symptoms mentioned in historical sources include severe headaches, fever, vomiting, and altered perception. According to the researchers, this picture would be consistent with bleeding or rapid swelling of a pituitary adenoma.
The new theory builds on earlier research by the same team, published in 2019, which argued that certain facial features attributed to Simonetta in portraits, including a slight squint, could point to a hormone secreting pituitary tumor. It’s worth noting this remains a theory built on highly uncertain evidence: there is no firm proof the portraits in question actually depict Simonetta Vespucci, nor that she was Botticelli’s inspiration for the famous painting at all.
The Woman Behind Venus
So who might the woman who inspired Botticelli actually have been? Simonetta Cattaneo was born in 1453 and married young to Marco Vespucci, a member of a prominent Florentine family and a relative of the explorer Amerigo Vespucci. Her arrival in Florence reportedly caused a sensation, and later accounts describe her as the most beautiful woman of her time, with her presence closely tied to the Medici court, particularly to Giuliano de’ Medici. Their rumored romance, like much about her personal life, isn’t historically confirmed. It is known, however, that at a grand jousting tournament in 1475, Giuliano named her “queen of beauty” and competed under a banner painted by Botticelli; the figure of Pallas Athena on that now lost banner is thought to have carried her likeness. A year later, Simonetta was dead.
The Other Candidate for Venus
A lesser known theory holds that the model wasn’t Simonetta at all, but Alessandra, or “Sandra,” Lippi, daughter of Botticelli’s own teacher Fra Filippo Lippi and the painter’s goddaughter. This version draws heavily on a historical novel by French author Sophie Chauveau, who compared the facial structures in “The Birth of Venus,” “Primavera,” and “The Abandoned Woman” and argued the same model appears in all three. Chauveau has acknowledged that the supposed romance between Botticelli and Sandra was her own literary invention, so this version belongs more to fiction than to settled history.
The Painting’s Mystery
“The Birth of Venus,” likely painted in the mid-1480s and now on display at the Uffizi Gallery in Florence, was created roughly a decade after Simonetta’s death. Her identification with Venus rests not on any documented sitting, but mainly on later interpretations and the legend that grew up around her connection to Botticelli.
Alessandra Lippi’s link to the painter, meanwhile, wasn’t incidental: she was the daughter of Fra Filippo Lippi, under whom Botticelli trained, and is said to have been named after him, her godfather. After his teacher’s death, Botticelli stayed close to the Lippi family, and Fra Filippo’s son, Filippino Lippi, later worked as Botticelli’s own student and collaborator.
It’s within that overlapping artistic and family circle that the theory places Sandra as a possible model for some of his female figures.
