Yoritomo died in 1200 at the age of fifty-three, his eldest son, Yoriiye, succeeding to the title of generalissimo. But Yoriiye being only eighteen years of age, and having given no evidence of ability, his mother, Masako, commissioned her own father Hōjō Tokimasa, together with twelve councilors, to assume the direction of the government at Kamakura. From this time began the dark age of Kamakura, in which unbridled ambition ignored all restraints of propriety. When the young Yoriiye fell ill in 1203, his mother, acting in concert with Tokimasa, planned to relieve him of his office of generalissimo, and to appoint his son Ichihata to be lord and governor general of the twenty-eight eastern provinces forming Kwantō, and his young brother Chihata--afterward called Sanetomo--to be lord of the thirty-eight western provinces forming Kwansei. This plot so incensed Yoriiye that the latter, with his wife's father, Hiki Yoshikazu, planned means to exterminate the Hōjō family. Tokimasa frustrated the design by having Yoshikazu assassinated, and then attacking and slaying all his blood relations together with Ichihata. Yoriiye he afterward shut up in a temple, and ultimately caused him to be put to death. Sanetomo, Yoriiye's younger brother, succeeded him, but exercised no administrative authority, the Hōjō holding everything in their own grasp. The shōgun consequently devoted himself to literature rather than to military exercises. Moreover, foreseeing that fortune would not long continue to smile upon the Minamoto family, he thought to obtain a high position in the central government, and add luster to the family's renown while there was yet time. Hence he was promoted to the post of chief councilor of state (_dainagon_), in conjunction with that of commander in chief of the guards of the left, his official rank being raised to the first of the second class. Shortly afterward he became lord keeper of the privy seal and then minister of the right. But in 1219, on the occasion of worshiping at a shrine in Kamakura, he was stabbed to death by Kugyō, a son of Yoriiye. This event terminated the descendants of the Minamoto family in the direct line. A brief interval of thirty-five years, or three generations,[2] from the time when Yoritomo had risen to the head of the government, sufficed to complete the supremacy of the great clan, the first shōgun of which had so systematically pruned off the useful members of its own branch.