The Christian Seas of Kyushu: How Local Maritime Networks Facilitated the Introduction of Catholicism to Japan in the Mid-Sixteenth Century

Using sources in both Japanese and Portuguese, this article examines how maritime connections on the island of Kyushu facilitated the spread of Christianity there during the Jesuit mission to Japan in the mid-sixteenth century. Part I builds upon recent Japanese-language scholarship on the prevalence of maritime activity and transportation on Kyushu and highlights the importance of so-called “sea peoples” for individual daimyo (regional lords) who ruled the island. Part II reveals how the first Jesuits, such as Francis Xavier, used preexisting maritime routes to missionize and founded new Christian communities along the coasts of Kyushu. Many Japanese Christians in these communities had expertise in maritime matters, which proved useful for transporting missionaries, going to church, fleeing persecution, and providing mutual assistance in times of need. In examining how local maritime networks and “sea peoples” facilitated missionization in Japan, we gain greater insight into how Christianity spread globally during the period.