The Japanese warrior chieftain Minamoto Yoritomo (1147-1199) founded Japan's first military government, or shogunate, in 1185 and thereby inaugurated the medieval period of Japanese history, which lasted until 1573.
In the 12th century, Japan was still ruled by the government of the imperial court in Kyoto and in particular by the courtier family of Fujiwara, which held the office of imperial regent and many other high ministerial positions at court. However, by regarding the provinces merely as a source of revenue from their private landed estates and by concerning themselves almost exclusively with life and affairs in the capital, the Kyoto courtiers sadly neglected provincial administration. The rise of a warrior class from about the 10th century stemmed directly from the need to provide order and control in the provinces.
By the 12th century, this emergent warrior class was dominated by two great clans, the Minamoto and the Taira, both of which traced their descent from the imperial family itself—that is, from former princes who had gone out to the provinces and had settled there. During the late 11th and the early 12th centuries, chieftains of the Minamoto and Taira increasingly came to participate in the politics of the court, and as the result of two armed conflicts in Kyoto, in 1156 and 1159, the Taira succeeded in supplanting the Fujiwara as the most powerful ministerial family in the land.
Period of Taira Dominance
Yoritomo was only 12 years old at the time of the 1159 conflict, in which the Taira decisively defeated the Minamoto, who were commanded by his father, Yoshitomo. Although his father was killed, Yoritomo's life was spared, and he was sent into exile in the eastern provinces of Japan by Kiyomori, the Taira leader.
During the next 20 years Kiyomori and his kinsmen, following the Fujiwara practice of marrying their daughters into the imperial family, were the unrivaled masters of the court at Kyoto. But they did little to improve provincial administration or to provide for the needs of the new warrior class in general. Beginning in 1180, several prominent Minamoto leaders, including Yoritomo, were encouraged by growing signs of discontent with the rule of the Taira in Kyoto to rise in arms against them.
Overthrow of the Taira
The war between the Minamoto and the Taira lasted from 1180 until 1185. In the early years of fighting Yoritomo devoted his attention mainly to the assertion of his leadership over the various branches of the Minamoto clan and to the consolida tion of his position as warrior hegemon in the eastern provinces. Even during the period from 1183 to 1185, when Minamoto armies drove the Taira from Kyoto to final destruction at the battle of Dannoura in the Shimonoseki Strait, Yoritomo himself remained in the eastern provinces to supervise the overall strategy of victory and to establish governing offices to exercise the powers that he had acquired.
Yoritomo established his new warrior regime at Kamakura, a small coastal village south of present-day Tokyo, where the Minamoto had long been influential. From the time of his first rising, in 1180 (when he had received a decree to destroy the Taira from a prince who, owing to Taira interference, had been passed over in the line of succession to the throne), Yoritomo had sought to "legitimize" all of his actions and to avoid being cast in the role of rebel by the throne. Among the titles he received from the Emperor after victory over the Taira, the most important was that of shogun, or "generalissimo." On the basis of this, the government Yoritomo founded, which lasted from 1185 until 1333, is known as the Kamakura shogunate.
The strength of Yoritomo's rulership lay in the feudal-type, lord-vassal relationships he established with his followers. In return for allegiance and military service, Yoritomo provided his vassals with protection, confirmed them in their existing landholdings, and bestowed new lands upon them.
Yoritomo's authority, which was restricted chiefly to the provinces of eastern Japan during the war with the Taira, was made national in scope in 1185, when he received permission from the throne to appoint his vassals as stewards to various private estates throughout the country and as constables or protectors in each province. Although the steward-constable system of the Kamakura period never fully displaced the old imperial administration in the provinces, and although many estates remained immune from all outside interference or control, the Kamakura shogunate nevertheless decisively replaced the imperial court at Kyoto as the effective central government of Japan.
Probably the greatest shortcoming of Yoritomo as a ruler was his failure to provide for effective succession to the office of shogun. Fearful that they might challenge his own position, Yoritomo had liquidated several of his brothers and other close relatives, and when he himself died at the age of 52, in 1199, his two young sons, who became the second and third shoguns, were unable to sustain the power of the Minamoto. Before long the Hojo family, who were related to Yoritomo by marriage, assumed control of the government at Kamakura as shogunate regents. To legitimize their position, the Hojo installed Fujiwara courtiers and, later, imperial princes as figurehead shoguns.
In contrast to Yoritomo, who had ruled in a generally autocratic fashion, the Hojo regents established a council of state at Kamakura that gave other warrior chieftains of the east the opportunity to participate more directly in the decision-making process of the shogunate.
Further Reading on Minamoto Yoritomo
An excellent book on Yoritomo and his times is Minoru Shinoda, The Founding of the Kamakura Shogunate, 1180-1185 (1960). For a more general treatment of the growth of a warrior class in Japan and the rise of Yoritomo to power see Sir George Sansom, A History of Japan, vol. 1 (1958).