Christian daimyo (キリシタン大名)
The Tensho Boy Mission to Europe (known as the Tensho Keno Shonen Shisetsu in Japanese) was sent to Rome together with Sumitada OMURA and Harunobu ARIMA.
The term "Christian daimyo" refers to those daimyo (feudal lords) who professed faith in Christianity.
The Warring States Period
Francis Xavier understood society in the Warring States period extremely well; first he sought permission to proselytize from daimyo all over Japan, and then, in order to ensure his missionary work would go smoothly, even began proselytizing to the daimyo themselves. Missionaries who came to Japan after Xavier's time also went to see daimyo in various places throughout Japan, and just as Xavier had, they obtained permission to spread Christianity in the domains of those daimyo, and also proselytized to the daimyo themselves. In order to win favor with these daimyo, and in return for permission to proselytize, some missionaries agreed both to support Japan's trade with Spain and Portugal and to provide them with weapons. Among the daimyo, there were some who professed their faith in Christianity in order to curry favor with the missionaries, hoping to get more such benefits from them. Christianity began spreading remarkably fast, especially in those domains whose daimyo had professed their faith. However, as Christianity continued to spread, some daimyo (notably Ukon TAKAYAMA) found themselves impressed with Christianity's doctrines as well as with the virtue and vigor of Christian daimyo, and chose to believe in the religion on their own initiative. The number of Christian daimyo continued to increase, even in landlocked regions and other areas unconnected the trade with Spain and Portugal.
Among those who became Christians, some daimyo and their retainers took heed of the missionaries' views and chose to burn or knock down temples and shrines in their territory. Among those daimyo who professed faith in Buddhism or Shinto, some took heed of the monks' or priests' views and branded Christianity, a foreign religion, a type of "heresy," oppressing its followers. In this way, hatred and opposition sprang up between those who believed in Christianity and those who professed faith in the older Japanese religions. Along these lines, Hideyoshi TOYOTOMI issued the Bateren Tsuihorei (an edict expelling the Jesuit missionaries), putting Christian daimyo under intensified political pressure. Many daimyo were forced to relinquish their samurai status and forfeit their hereditary territories, or were compelled to profess faith in Buddhism or Shinto (compulsory conversion), ushering in a period of anti-Christian edicts and persecution of Christianity.
The Edo Period
After the Edo period began the Ban on Christianity was issued in 1613, as a consequence of which Ukon TAKAYAMA, who refused to the very last to recant his Christian faith, was banished to Manila, and Harunobu ARIMA was executed; from that point onward there were no more Christian daimyo.
Most of the Christians in their territories converted to Buddhism or became crypto-Christians. Yet many Christians were to suffer a far more dramatic end, vanishing from the scene after being slaughtered during the Shimabara Rebellion, a large-scale uprising which occurred in the former territory of Harunobu ARIMA.