But Yedo itself was not very old. Towards the close of the fifteenth century, a renowned warrior, Ota Dokan by name, built a little castle in the village of Yedo. Not long after his death, his family became extinct and others succeeded to the lordship of the little castle. A century later, Tokugawa Iyeyasu, one of the most powerful daimyo, or territorial lords, at the time, became master of the Eight Provinces east of the Hakone Mountains and was on the point of establishing his government at Kamakura, the capital of the first line of Shogun, when he was persuaded by his suzerain, the Taiko Hideyoshi, who is best known to history for his invasion of Korea, to set up his headquarters at Dokan’s castle-town which possessed great strategic advantages over Kamakura. Accordingly, in 1590, Iyeyasu came to the village of Yedo and saw that the castle could be developed into a formidable fortress. At once he set to work rebuilding it on a gigantic scale. Bounded on the north and west by a low line of hills, on the south by the Bay of Yedo, and on the east by marshes, it was in those days of bows and arrows and hand-to-hand fights almost impregnable. Behind the hills lay the wide plain of Musashino, across which no enemy could approach unobserved, while it was equally difficult to make a sudden attack upon the castle from the sea or over the marshes. The castle covered upwards of five hundred acres within its inner walls. The swamp was reclaimed, and merchants, artisans, priests, and men of other crafts and professions were induced by liberal offers to settle in the new city. The reclaimed land soon became the principal merchant quarter.