The whole of Japan was now under Hideyoshi's sway except the fiefs in the extreme north and those in the region known as the Kwanto, namely, the eight provinces forming the eastern elbow of the main island. Seven of these provinces were virtually under the sway of Hojo Ujimasa, fourth representative of a family established in 1476 by a brilliant adventurer of Ise, not related in any way to the great but then extinct house of Kamakura Hojos. The daimyos in the north were comparatively powerless to resist Hideyoshi, but to reach them the Kwanto had to be reduced, and not only was its chief, Ujimasa, a formidable foe, but also the topographical features of the district represented fortifications of immense strength. After various unsuccessful overtures, having for their purpose to induce Ujimasa to visit the capital and pay homage to the emperor, Hideyoshi marched from Kioto in the spring of 1590 at the head of 170,000 men, his colleagues Nobuo and Iyeyasu having under their orders 80,000 more. The campaign ended as did all Hideyoshi's enterprises, except that he treated his vanquished enemies with unusual severity. During the three months spent investing Odawara, the northern daimyos surrendered, and thus the autumn of 1590 saw Hideyoshi master of Japan from end to end, and saw Tokugawa Iyeyasu established at Yedo as recognized ruler of the eight provinces of the Kwanto. These two facts should be bracketed together, because Japan's emergence from the deep gloom of long-continued civil strife was due not more to the brilliant qualities of Hideyoshi and Iyeyasu individually than to the fortunate synchronism of their careers, so that the one was able to carry the other's work to completion and permanence. The last eight years of Hideyoshi's life--he died in 1598--were chiefly remarkable for his attempt to invade China through Korea, and for his attitude towards Christianity (see § VIII.: FOREIGN INTERCOURSE). _The Tokugawa Era._--When Hideyoshi died he left a son, Hideyori, then only six years of age, and the problem of this child's future had naturally caused supreme solicitude to the peasant statesman. He finally entrusted the care of the boy and the management of state affairs to five regents, five ministers, and three intermediary councillors. But he placed chief reliance upon Iyeyasu, whom he appointed president of the board of regents. Among the latter was one, Ishida Mitsunari, who to insatiable ambition added an extraordinary faculty for intrigue and great personal magnetism. These qualities he utilized with such success that the dissensions among the daimyos, which had been temporarily composed by Hideyoshi, broke out again, and the year 1600 saw Japan divided into two camps, one composed of Tokugawa Iyeyasu and his allies, the other of Ishida Mitsunari and his partisans. Iyeyasu.