This article examines the position of the de’ Grassi brothers, Agamemnon, Achilles, and Paris, as diplomats and negotiators between Rome and Bologna. During Julius II della Rovere’s pontificate, relations between these cities were strained as the pope worked to permanently dislodge the usurping Bentivoglio family from power and to govern Bologna through an expanded patrician council (the Quaranta Consiglieri). As a member of the Quaranta, Agamemnon commandeered his brothers’ skills and resources to improve Bolognese relations with the pope. The other brothers, as members of the papal court, could press Bologna’s cause using their professional knowledge and contacts. As a reward for their support, in 1511 Julius provided Achilles with a cardinal’s hat and shortly thereafter the bishopric of Bologna, which immediately was challenged by the Bentivoglio faction. Although all three brothers privileged their dual loyalty, in the aftermath of the Bentivoglio expulsion in 1512, the pope’s anger with Agamemnon as a Bolognese orator reveals the malleability of civic patriotism and political allegiance.