In the aftermath of the reformation, Bavaria became the Roman Curia’s most important partner in the Holy Roman Empire, alongside the emperor. Catholicism lay at the heart of this stable network, which soon engaged all levels of exchange. A long tradition of close diplomatic ties between Munich and Rome began when duke Maximilian sent an official envoy to the Holy See for the first time in 1605. During the Thirty Years’ War, contacts intensified. The Curia associated Wittelsbach with the catholic columns in Germany. For the pope, Maximilian represented the most vigorous leader in the wars of religion against the protestants. The two strategies of subsidizing his dwindling military funds and supporting his political ambitions to preserve his newly acquired status as prince-elector on behalf of Bavaria strongly marked the Curia’s stance towards Germany. The correspondence of the nuncios at the court of Vienna broaden this perspective: by shedding light on the period around the 1630s, they help us to understand Maximilian’s relationship with Rome from an external point of view. The documents focus on the ways in which Urban VIII and his representatives promoted the cause of Munich at the imperial court. In close cooperation with Maximilian, papal diplomacy accompanied his quest for prestige and power in Early Modern Europe by using an intricate set of policy-making tools: asserting Bavaria’s place within the framework of international states – as a Stato in its own right – was one of their most effective methods.