The establishment of martial government at Kakamura in the late twelfth century by Yoritomo Minamoto, chieftain, was a major event in Japanese history. It initiated the shogunate and a period of organized feudalism which was to last for more than six hundred years. The basis for Japan's unique form of dual government was laid. The provincial warrior class rose to power as the civilian aristocracy declined. The nation's political center shifted from Western Kyoto, a stronghold of Chinese learning, to eastern Kakamura, largely untouched by tradition and cultural refinement. In consequence, martial values were exalted, Chinese influence dwindled, and a new, distinctively Japanese culture arose and was rapidly diffused.
All of these important developments resulted from what had begun as a relatively minor struggle between two rival families, the Taira, or Heiji, in power in 1180, and the Minamoto, or Genji, who raised the standard of revolt.
The victory of the Minamoto forces and the establishment first of a small military headquarters and eventually of a nationwide government were due largely to the personal qualities and the good fortunes of one man: Yoritomo, chieftain of the Minamoto.
Minoru Shinoda's study of the founding of the Kamakura shogunate embraces the historical background of the revolt, the various phases of the war, and the successive steps by which Yoritomo's headquarters became the source of redress for grievances and, ultimately, the seat of civil government.
A generous selection of translations from the Azuma kagami, or Mirror of Eastern Japan, gives the Western reader a hitherto non-existent access to the principal sources for the crucial years 1180-1185. A semi-official history, now recognized as having been compiled sometime after 1266, it comprises, in versions still extant, fifty-two chapters covering a period of eighty-six years, written as a day-to-day account.
The portion here presented includes copies of official documents and correspondence, petitions and reports. The military and political accounts are interspersed with pictures of the social and family life of the day. Religious rites, banquets, and excursions are described. The new buildings at Kamakura are referred to with naive pride; the far-reaching consequence of wifely jealousy are detailed.
And the whole of the record is dominated by the character of Yoritomo, a man in whom the Kyoto aristocrat and the provincial warrior are blended to produce the leader needed at the time. Only such a man could have made possible the establishment and the nationwide acceptance of the dual government which was to last, with only occasional interruptions, until the latter half of the nineteenth century. With his virtues and his faults, he emerges here as a man of destiny, the importance of whose role in Japanese history can only now be fully assessed.