By the end of the sixteenth century, the Japanese mission had become the largest overseas Christian community that was not under the rule of a European power. Its uniqueness was emphasized by Alessandro Valignano since 1582, who promoted a deeper accommodation to Japanese culture. It was also understood by Toyotomi Hideyoshi, who issued the first national anti-Christian laws while he was unifying the Japanese empire. The main reason the religious success of the Catholic Church in Japan was, undoubtedly, the engagement of many converts and their descendents. This article deals with the role of Japanese lay people within the Church, analyzing how individuals gave support to daily activities and how the communities strengthened themselves through the formation of brotherhoods. Japan was then the sole overseas country where all members of those confraternities were locals, in spite of the presence of a colonial elite. KEYWORDS: Portuguese - Japanese Christianity - local communities - brotherhoods (ProQuest-CSA LLC: ... denotes non-USASCII text omitted.) The Portuguese sustained contact with the Japanese nearly a century (1543-1639).1 The main reason the regular visits of the nanbanjin ... (southern barbarians) to the islands was trade, since the Portuguese controlled much of the Sino-Japanese commerce several decades and founded two new and distinctive cities in the China Sea region: Macao and Nagasaki.2 The ships that sailed between those cities, however, did not carry only goods trade. They also brought men of different races, animals, many objects (such as glasses, chairs, buttons, or firearms), and scientific knowledge in areas such as geography, medicine, astronomy (see Nakayama 1969) and mathematics (Leitao 2000), which opened a new era in Japan. After centuries of isolation from Europe, Japanese civilization acquired a more accurate understanding of Earth and an awareness of contemporary technological developments.3 The Portuguese, in turn, were initially received by a medieval and anarchic society in the mid-sixteenth century, and were subsequently expelled a century later by a modern and centralized empire. The sengoku had been replaced by the taihei-an evolution that cannot be explained without reference to the nanbanjin contributions (Nosco 2003), who exhibited for once [...] a genuine international dimension in a period of Japanese history (Elison 1981, 60). Along with European trade goods and Western cultural influences a new religion also came to Japan. The propagation of Christianity was always one of the motivations which pushed the Portuguese during the Age of Discoveries.4 There was a sincere desire that Christendom would profit from those voyages, enlarging the areas and the populations under the leadership of the Catholic Church, and by the 1460s the Portuguese Crown acquired absolute control of overseas ecclesiastic activities. Later, from the middle of the sixteenth century, when private traders became more autonomous, pushing Portuguese influence to areas where state authority was weak, those adventurers also brought with them clergymen, just as the king's representatives had done before.5 Therefore, the arrival of Portuguese explorers to Japan in 15436 opened a new field to missionary activity, and the first clerics of the Society of Jesus landed in Kagoshima in 1549.7 Christianity in Japan A SUCCESSFUL MISSION The Jesuits were able to found a sizable community in Japan, which had about three hundred thousand baptized by the end of the sixteenth century. It was at the time the largest and most important overseas Christian community not under the control of a colonial power, as was the case with Christian missions in Mexico, Peru, Brazil, the Philippines, or India.8 Most Japanese Christians lived in Kyushu, but Christianization was not a regional phenomenon and had a national impact. By the end of the sixteenth century it was possible to find baptized people in virtually every province of Japan,9 many of them organized in communities. …