Arima Harunobu (有馬 晴信, 1567 – June 5, 1612) was a Japanese samurai lord who was the daimyo of Shimabara Domain and the head of the Hizen-Arima clan from Hizen Province.
As a result of his conversion to Christianity, Harunobu started to receive weapons from the Portuguese, which strengthened the Arima clan.
Harunobu also founded a seminary and training center for novices in his domain where, apart from the ordinary curriculum, students were also taught European music, painting and sculpture and the manufacture of organs and pocketwatch.
[1] In 1582 Harunobu teamed up with the Kyūshū Christian daimiyōs Ōtomo Sōrin and Ōmura Sumitada to send a Japanese embassy to the Pope in Rome, led by Valignano and represented by Mancio Itō.
In 1586, he had a vision in which there appeared to him two persons of celestial exterior, who thus spoke to him: "Know that on the lands over which you rule, the sign of Jesus is found; honor and love it much, for it is not the work of man."
On his arrival the young man noticed a tree that was somewhat dried up; he split it in two, and found inserted in the middle of it a cross of a brown color and of a regular form.
As soon as Harunobu heard of this, he went to the place, and on seeing the cross he cried out: "Behold the sign of Jesus, that I was told was hidden in my dominions, and that was not made by the hand of man."
Harunobu retaliated the following year by attacking the Portuguese trading ship Madre de Deus, bound for Nagasaki from Macau.
A certain Okamoto Daihachi, who was a servant of Tokugawa Ieyasu's close advisor Honda Masazumi, was sent to Harunobu to congratulate him on his triumph against the Portuguese.
St. Alphonsus Liguori wrote of his death as follows: The emperor had deposed and exiled him, in consequence of an odious intrigue concocted against him by his own son, named Michael.
In his exile King John led a very penitent life, to repair all the bad example that he had given, and he desired nothing so much as to expiate by his death his past iniquities.
The latter, taking counsel only of the hatred that he bore him, condemned him without trial to be beheaded, and sent one hundred and fifty soldiers to carry out the sentence.