Note: There is another copy of this letter in Mediceo del Principato 2955, insert no. 11, fols. n.n. [Entry 5150 in the "Documentary Sources" database.]

TRANSLATION:
7 February 1619
Most Serene and Esteemed Lady, my Sister:
I have been warned that lord Don Giovanni [de' Medici] is coming to spend carnival in Mantua, and that he is bringing that woman [Livia Vernazza] with him. While the first part of this plan pleases me, believing that Your Highness will enjoy seeing him again in the bosom of that family, the second part disturbs me, not knowing under what title he is escorting this woman, nor in what manner she might be received by the lord Duke [Ferdinando Gonzaga] and by Your Highness [Caterina de' Medici]. In either case, as your most loving brother I wanted to tell you secretly, as I am now doing with this express courier, that I consider that woman to be nothing less than a whore. If I were certain that he had married her, or that he was about to marry her, I should not wish him ever again to be considered a member of this family and I would behave as though I had never known him. However, I find it difficult to believe that a man of such prudence and wisdom could be capable of so great an error. May the Lord God hold his hands over you and I attentively kiss your hands. From Florence, 7 February 1618 [1619 in modern dating]
Your most affectionate servant and brother,
The Grand Duke of Tuscany [Cosimo II de' Medici]

TEXT:
Ser.ma Sig.ra mia sorella Oss.ma
Ho presentito che il Sig.r Don Giovanni [de' Medici] viene a far costà il carnevale, et che mena seco quella sua femina [Livia Vernazza], et si come la prima parte di questa sua resolutione mi piace, credendo che V.A. haverà caro di rivederlo in cotesta casa, così la seconda mi da fastidio, non sapendo sotto che titolo egli conduca detta donna, nè in che forma ella possa esser trattata dal S.r Duca [Ferdinando Gonzaga] et da V.A. [Caterina de' Medici]. Et per ogni caso come affetuossisimo fratello dell'A.V. ho voluto confidentemente avvertirla, come faccio per corriere espresso, che io non tengo detta donna se non per puttana, et quando fossi certo o che egli l'havesse sposata, o che fosse per sposarla, non vorrei che fosse mai più chiamato di questa famiglia et farei conto di non haverlo pur conosciuto, ma difficilissimamente mi accomodo a credere così grande errore d'un huomo di tanta prudenza et saviezza. Et il S.re Iddio gli tenga le mani in capo, et a V.A. bacio di cura le mani. Di Fiorenza 7 febbraio 1618 [1619 stil. mod.]
Affetuossisimo Servitore et Fratello
Il Granduca di Toscana [Cosimo II de' Medici]

HISTORICAL BACKGROUND:
In February of 1619, the carnival season was getting underway at the Gonzaga court, presided over by Ferdinando Gonzaga, the 6th Duke of Mantua (1586-1626) and his consort Caterina de' Medici (1593-1629), sister of Cosimo II, the reigning Grand Duke of Tuscany. As in most Italian cities, this festive season was celebrated in Mantua with frolicsome events including masked balls, elaborate theatrical and musical performances and extravagant banquets. For the carnival of 1619, the Gonzaga court was also expecting a visit from Caterina's uncle, Don Giovanni de' Medici (1567-1621), the illegitimate son of Grand Duke Cosimo I de' Medici. Don Giovanni was an acknowledged member of the Medici family who had distinguished himself both as a military leader and an amateur architect. Though a welcome guest in his own right, it was rumored that Don Giovanni planned to come to Mantua with his paramour Livia Vernazza, the disreputable daugher of an Genoese mattress maker to whom he might or might not be married. This circumstance raised delicate issues of ceremonial protocol, for it was not clear how the couple should be received at the Gonzaga court.
We know from other documents that Don Giovanni did indeed come to Mantua for the Carnival but was prevailed upon to lodge his lady companion with a private family--not at court as a state visitor. (Mediceo del Principato 2949, fol. 18; Entry 2949 in the "Documentary Sources" database.) When Don Giovanni died in Venice two years later, he left Livia Vernazza with two very young children. Though apparently legally married, the Medici (true to their word) refused to accept the union and Livia spent the rest of her life under house arrest in a Tuscan villa.