The second phase of the dispute is characterised by the confrontation between Margaret and Caterina, who in 1547 became Queen of France. These two powerful women engaged in a legal and diplomatic confrontation over the legitimacy of their rival claims to the Medici heritage. The dispute ended with an agreement negotiated in Rome by the preeminent notary Antonio Massa in 1560. After which, it was established that, with the exclusion of a range of movable goods acquired by Margaret as compensation for her dowry, Caterina was to be considered the formal owner of the Medici estate, while Margaret could enjoy custodianship for the remainder of her life.

François Clouet, Portrait of Caterina de’ Medici, black and red chalk, c. 1550, The British Museum, London