Governmentality rationales and calculative devices: The rejection of a seventeenth-century territorial barter proposed by the King of Spain

Almost 400 years ago, Ferdinando Gonzaga, Duke of Mantova and Marquis of Monferrato, refused a territorial barter proposed by the King of Spain, who had offered the Isle of Sardinia in exchange for the Marquisate of Monferrato. In 1618, an advisor to the Duke drafted a report to highlight the governmental issues surrounding the island. This Relatione, together with correspondence between the governors and advisors engaged in the prospective transfer, reveals why the Duke rejected the proposal. These sources provide the foundation for a close analysis of the potential effects of the trade on the Duchy's welfare, as well as the problems associated with its government. Using a model based on the Foucauldian governmentality framework, this analysis reveals that denying the barter was the result of rational behavior, driven by territorial governability aims