 Born into one of the most important families of the Florentine patricians, Camilla was the daughter of Antonio Martelli and Fiammetta Soderini.After the death of Cosimo's first wife Eleonora of Toledo and after the end of his relationship with Eleonora of Albizi, Camilla became Cosimo's lover despite being 26 years his junior.Camilla stood by him during his old age, when because of his poor health he retired to private life in the villa di Castello, abdicating in favour of his son Francesco I de' Medici.