1 Doppia - Ferdinand Gonzaga

Ferdinand Gonzaga became Duke of Montferrat in 1613 through his branch's inheritance of the marquisate, but his hold on the territory was never settled — Spain, Savoy, and the Empire all had competing claims that would eventually ignite the War of the Mantuan Succession after his death. This doppia was struck during the narrow window when Ferdinand held Montferrat without active military contest, making the 1617–1618 dating significant: within a decade, the duchy would be devastated by plague and foreign armies fighting over exactly this succession.