Keywords: Genoa; Court of Modena; Italian Diplomacy; Grimaldis; Patronage.
Linked to their patrons, the Este family between the 1630s and 1640s the Genoese Grimaldi de Castro engaged in an informal diplomacy on behalf of the Duchy of Modena. Their inclusion in Spanish and Genovese systems of power is an example of an eclectic diplomacy that ranged between formality and informality. For its part, the court of Modena supported the Grimaldis' private interests while praticing its diplomacy in Madrid. The story of the relationship between Modena and the Grimaldis intertwines diplomacy and private interests, unfolding in a context that was complicated by international upheavals, and by the resulting changes in the policies of the Duchy of Modena and the Republic of Genoa.