On February 5, 1597, six Franciscan friars, three Japanese Jesuits, and seventeen Japanese Catholics were crucified in Nagasaki, prompting recriminations among the religious orders that were fighting over the right to evangelize Japan. In 1600 Pope Clement XIII intervened by promulgating a brief, Onerosa pastoralis, declaring that missionaries could go to Japan only via Lisbon and then Goa, and that none could travel there along the western route which passed through Mexico and the Philippines. In the letters below, a Franciscan friar and a Dominican friar protest the papal brief, providing a window into the ongoing tensions among different missionary orders and different imperial projects that were a common feature of the early modern Iberian empires, and which the martyrs of Nagasaki had brought to the surface.

In theory, the scope of Iberian imperialism was set by the Treaty of Tordesillas in 1494, when an agreement was made between the Spanish and Portuguese, overseen by Pope Alexander VI, defining which areas each was allowed to explore and evangelize to the exclusion of the other party. The religious organization of these spaces depended on the padroado in the Portuguese sphere and patronato real in the Spanish. These concessions were granted by the pope to the respective kings over ecclesiastical appointments, among other things, and so where a territory lay affected which king could send missionaries. The original boundary cut through the Atlantic Ocean and South America, and the 1529 Treaty of Zaragoza extended it around the globe, into the Pacific Ocean.