The Gempei War is a period of Japanese history that, while relatively short in duration, is a major turning point: the end of direct rule by the imperial court, the beginning of warrior rule, and the shifting of the locus of government to the east have all been traced back to the Minamoto victory over their Taira foes. It is no surprise that such a momentous event in Japanese history should be commemorated in several genre ranging from war tales meant to be read or performed, small dramas called kōwakamai, and “histories” that were compiled by the Minamoto victors. Elizabeth Oyler's purpose in this study is to point out that the boundaries between these seemingly distinct genres were always rather fluid in medieval Japan and to examine how these disparate stories were interwoven to create the shared “history” of the period.

Oyler first analyzes Yoritomo's “dream interpretation” that takes place shortly before he raises a rebellion against the Taira and that seems to provide divine sanction for what later will become the bakufu. It seems as if the gods themselves, especially the Minamoto patron deity, Hachiman, favor the Minamoto and thus implicitly give their blessing to the establishment of Minamoto hegemony. The dream itself, however, is not the main focus of the narrative, but rather the interpretation of the dream, which foregrounds the interpreter as enabler and seems to foreshadow the Minamoto role not as warrior, but as law giver and adjudicator of legal disputes. Oyler sees this emphasis on divine favor as instrumental in creating the historical memory of the Minamoto as the agents of stability and order in medieval society that justified their role as rulers of Japan.

In chapters 2 and 3, Oyler attempts to deal with the inherent paradox between familial infighting and the institutional stability and solidarity represented by the Minamoto rulers. She does this by examining the stories behind Yoshinaka, a cousin of Yoritomo, and Minamoto Yoshitsune, the shogun's brother. In both cases, these warriors were eminently successful in battle against the Taira, and in both cases ended up being eliminated by the shogun's forces. In both cases the role of the written petition takes on special significance. In the first case, Yoshinaka petitions the god Hachiman for victory against the Taira and is rewarded when the Taira are forced to retreat. In Yoshitsune's case, he writes a petition to Yoritomo protesting his innocence, but is rejected by the shogun and forced to flee his brother's wrath. The use of writing (by a talented scribe) seems to point to a new era in which government is carried out not simply by the whim of the rulers, but by a rational system of laws that are promulgated at Kamakura. Finally, in both instances, the familial feuding between the Minamoto warriors is glossed over, either through the use of an “evil-intentioned outsider,” in the case of Yoshitsune, or through a shortcoming in the hero himself, as in the case of Yoshinaka. Thus, although there were originally many rifts within the Minamoto family, later histories portrayed the Minamoto as a unified whole under the capable leadership of Yoritomo.

In the last chapter, Oyler examines the story of the Soga brothers' revenge on the murderer of their father and the almost supernatural swords used to carry out their revenge. The importance of this story is not so much the brothers and their mission, but rather the swords that they use. Many of the narratives take special pains to point out that these swords have a long and distinguished lineage going back at least to the Minamoto patriarch Yoshiie. The swords also, at one time or another, belonged to either Yoshinaka or Yoshitsune, imbuing them not only with a distinguished lineage, but also a tragic past. While both brothers ultimately are killed in carrying out their mission, the two swords are presented to Yoritomo, creating a situation in which distinguished family heirlooms are returned to their rightful owner. Thus, the swords' return symbolizes very powerfully the consolidation of Minamoto rule over Japan and the end of any real strife within the realm.

Oyler succeeds brilliantly on two points. She points out that the boundary between performance genre and history is not as rigid as we perceive it to be in the modern world. A good example of this is Yoshitsune's petition at Koshigoe in which he declares his innocence. This petition was set apart from the recitative text in performance pieces so as to give it an air of veracity. Compilers of later histories, in turn, used that “historical” text in their compilations of official histories, thereby furthering the text's claim to historical accuracy. Thus, the interplay between performance pieces and history is rather fluid.

Oyler also succeeds in pointing out that the “history” of the Gempei War and the Minamoto ascendancy was in fact woven from a number of disparate sources, some performance pieces, and some ostensibly objective “histories.” A number of variations on that history can still be seen in medieval dramas that portray the Minamoto family not as an undivided whole, but as something rather messier. Where Oyler succeeds less spectacularly is in her stated goal to “make a somewhat unfamiliar body of medieval work accessible to a wider readership” (p. xi). While her goal is a laudable one, this work is clearly written for those who are already familiar, at least in passing, with the history and literature concerning the Gempei War. Had she wanted to bring the subject material to a wider audience, she might have expanded upon her 149 pages of text, but nonetheless, this should in no way detract from the many successes that she achieves in this important work.