From its foundation in 1622, the Congregation de Propaganda Fide held supreme jurisdiction over all missionary activities of the Catholic Church at the global level, with authority coming directly from the pope. Its main goals were the expansion of the Catholic faith, the reaffirmation of papal spiritual primacy, and the promotion of Indigenous clergy throughout the world, which put Propaganda Fide in direct competition with secular rulers who also wanted to control missionary activities in their overseas territories. This article will examine one such conflict, namely that regarding Portugal and its royal patronage system in China. The Historical Archive of Propaganda Fide in the Vatican City holds extensive material concerning Portuguese patronage and China, which has remained relatively unknown and understudied. Through an examination of several of the most significant documents, such as the formal terms sent by the Portuguese court to the Holy See, the response of Propaganda Fide, and the final declaration of the Holy See, which would become the cornerstone for all future decisions over the patronage system, it is suggested that these negotiations about China are in fact central to a wider shift in global Catholic policy and politics in the field of missionary activity.