Neither of Cosimo's two sons was a suitable heir; Ferdinando was an alcoholic and epileptic, while his younger son, Gian Gastone, according to historian Paul Strathern, was not appropriate material for the role of sovereign.
Kumbki Cosimo kahest pojast ei olnud sobiv pärija; Ferdinando oli alkohoolik ja epileptik, samas tema noorem poeg Gian Gastone ei olnud ajaloolase Paul Stratherni järgi valitsejaks sobiv.