In A.D. 1592 Taiko Sama had by one of his wives a son, whom he named Hideyori. Over this new-born heir, whom, however, many suspect of not being Taiko Sama's son, he made great rejoicing throughout the empire. He required his nephew to adopt this new-born son as his heir, although he had several sons of his own. The result of this action was a feeling of hostility between the uncle and nephew. Hidetsugu applied to Mori, the chief of Chosu, to aid him in the conflict with his uncle. But Mori was too wary to enter upon such a contest with the veteran general. Instead of helping Hidetsugu, he revealed to Taiko Sama the traitorous proposition of his nephew. Hidetsugu was thereupon stripped of his office and sent as an exile to the monastery of Koya-san in the province of Kii. A year later he was commanded with his attendants to commit _hara-kiri_; and with an unusual exhibition of cruelty, his counsellors, wives, and children were likewise put to death.
Hideyoshi had for a long time contemplated the invasion of Korea and ultimately of China. In a conversation with Nobunaga when he was about to set out on his conquest of the western provinces he is represented as saying(177): "I hope to bring the whole of Chugoku into subjection to us. When that is accomplished I will go on to Kyushu and take the whole of it. When Kyushu is ours, if you will grant me the revenue of that island for one year, I will prepare ships of war, and purchase provisions, and go over and take Korea. Korea I shall ask you to bestow on me as a reward for my services, and to enable me to make still further conquests; for with Korean troops, aided by your illustrious influence, I intend to bring the whole of China under my sway. When that is effected, the three countries [China, Korea, and Japan] will be one. I shall do it all as easily as a man rolls up a piece of matting and carries it under his arm." He had already carried out part of this plan; he had brought the whole of Chugoku and of the island of Kyushu under his rule. It remained for him to effect the conquest of Korea and China in order to complete his ambitious project.
For this purpose he needed ships on a large scale, for the transportation of troops and for keeping them supplied with necessary provisions. From the foreign merchants, who traded at his ports, he hoped to obtain ships larger and stronger than were built in his own dominions. It was a great disappointment to him when he found this impossible, and that the merchants, whom he had favored, were unwilling to put their ships at his disposal. It is claimed by the Jesuit fathers that this disappointment was the chief reason for the want of favor with which Hideyoshi regarded them during the last years of his life. It is also advanced as one reason for his entering on the invasion of Korea, that he might thus employ in distant and dangerous expeditions some of the Christian princes whose fidelity to himself and loyalty to the emperor he thought he had reason to doubt. He was ambitious, so they said, to rival in his own person the reputation of the Emperor Ojin, who rose in popular estimation to the rank of Hachiman, the god of war, and who is worshipped in many temples, because, while he was still unborn, his mother led a hostile and successful expedition into this same Korea.