The Gempei War (1180-1185) was a Japanese civil war that pitted two great warrior clans - the Taira and the Minamoto - in a struggle for control of Japanese politics. Immortalized through the eyes of the losing Taira in the Tale of the Heike*, the Gempei War brought an end to Japan's fabled Heian Era, and ended with the establishment of what was to be the first of many shogunates, or military governments - the Kamakura bakufu.

A Call to Arms

The Gempei war began in 1180 when Emperor Takakura abdicated and the head of the ascendant Taira clan, Taira Kiyomori, installed his 2-year-old grandson Antoku as emperor at the expense of the legitimate heir, Prince Mochihito. In an extraordinary turn of events Mochihito, rather than accede to the wishes of the vastly more powerful Kiyomori, issued a general call to arms on his own behalf. This call to arms was picked up by a smattering of disgruntled provincial warriors, including Minamoto Yorimasa, leader of remnants of the Taira clan's old enemy, the Minamoto, who had been all but destroyed in the wake of Kiyomori's triumph in the Heiji Incident of 1160.

The Taira responded quickly and brutally to this threat to their authority, and with in a few months Mochihito was dead, and Yorimasa had been crushed at the Battle of Uji. But a fire had been lit, and would not so easily be quenched. Years earlier, Kiyomori had made a crucial error. After defeating Minamoto Yoshitomo in the Heiji Incident, rather than killing Yoshitomo's three infant sons, Yoritomo, Noriyori, and Yoshitsune, he had exiled them to the distant province of Izu. Now the eldest brother, Yoritomo, took up the Minamoto banner against the Taira.

The Rise of Yoritomo

Yoritomo renewed the call to arms against the Taira, and his nacent revolt soon assumed social and economic overtones. In the 8th month of 1180, Yoritomo issued a war declaration in which he made several astonishing claims. First, he asserted personal lordship over the Eastern provinces of Japan. Second, he offered to confirm under his own name the offices and land grants of any warriors who would follow him. Finally, and most audaciously, he declared that he would begin issuing new land grants to his followers, presumably to be taken from the confiscated lands of enemies. Yoritomo's declaration was a clear and unprecedented usurpation of authority normally reserved exclusively for the nobility of the Kyoto court, and constituted the first non-central locus of real political power in Japan's recorded history.

From 1181-1182 the war, which had started with so much pyrotechnics, entered a lull period, for despite all his bold words, Yoritomo as yet had no army, and needed time to organize an effective coalition of eastern warrior clans. The aging Kiyomori, a generation older than Yoritomo, passed away in February, 1181, leaving the Taira in a state of equal disarray. Meanwhile, the country plunged into anarchy and lawlessness as wandering warrior bands took advantage of the breakdown in centralized authority to pillage and loot and local warlords used the war as a pretext to attack local rivals and challenge the hierarchy of the shoen system, refusing to pay taxes, seizing lands from peasants, etc.

Minamoto Triumph

By 1183, however, Yoritomo was finally ready to make his move. Minamoto forces under his cousin Minamoto Yoshinaka ambushed and routed the Taira at Kurikawa and won again at Shinohara. In August, the Minamoto entered Kyoto in triumph as the Taira under Kiyomori's son Taira Munemori fled to the west with the infant Emperor Antoku. In a calculated symbolic gesture, Yoritomo remained at his eastern headquarters at Kamakura and sent emissaries to Kyoto to negotiate a settlement with retired emperor Go-Shirakawa - Yoritomo would not grovel before the court. An agreement was quickly reached by which Kamakura became an autonomous policing branch of Japan's legitimate government, while the infant Emperor Go-Toba was placed on the throne.

The Minamoto forces, now led ably by Yoritomo's brothers Noriyori and the legendary Yoshitsune, spent the next year and a half mopping up Taira power on Shikoku and preparing for the final assault on the last Taira stronghold in northern Kyushu. Meanwhile other Minamoto allies were busy battling endemic outlawry. Finally, on April 24, 1185, the Minamoto fleet trapped the Taira fleet off the Dannoura penninsula and wiped out the remnants of the once mighty Taira clan. Kiyomori's widow leapt into the sea with young Antoku in her arms, drowning both, and was followed in drowning by Taira Tomomori and many other leading Taira. The cowardly Munemori was captured and executed. The Gempei War was over.

Aftermath and Conclusions

By the end of 1185, Yoritomo secured a second agreement with Go-Shirakawa that granted him unprecedented powers. The court authorized Yoritomo sole control over a new system of warrior police made up of the shugo (constables assigned to imperial provinces) and the jitô (stewards assigned to oversee shoen). Yoritomo quickly began granting these offices to his own vassals, who soon turned them into lucrative vehicles for self-aggrandizement. At first glance, this new system appears to have given Yoritomo tremendous personal power at great cost to the authority of the Kyoto nobility, for he now unilaterially controlled a national constabulary loyal only to himself from his headquarters at Kamakura (previously, all power had eminated from Kyoto alone).

It is important to note, however, that Yoritomo was still very much dependant on a system of alliances to maintain his new government - although the jito and shugo were technically his vassals, he could not rule without their support, and thus still had to negotiate and conciliate to maintain his position of power. As for the Kyoto court, despite the concentration of power in warrior hands, the nobility still maintained much of its former prestige and even political influence. Indeed Kamakura seems to have shown a genuine respect for courtly learning and culture, and a desire to retain courtly traditions of the Heian Era. For example, the Lady Daibu was recalled to court and had her poetry published and the poet Fujiwara no Teika flourished in this period.

In this sense, Yoritomo's revolution was profoundly conservative - neither he nor his successors made any real efforts to undermine the perogatives of court or extract further concessions - the warriors appear to have been content with maintaining the status quo after 1185. Thus it would be incorrect to say that the establishment of Japan's first shogunate entailed the replacement of courtly government with warrior government; rather, the aftermath of the Gempei War represented the expansion of the polity from one government with one locus of power to two governments that shared power more or less equally - it was a dual polity, a dyarchy.

Nevertheless, change was in the wind, and the court, despite appearances, had irrevocably relinquished much of its power into the hands of warrior government. The nobility in Kyoto would henceforce have to share the stage with a new military aristocracy that was rapidly developing traditions and culture of its own. Over time, the new Kamakura Era would witness increasing friction between these two systems of authority, a friction that would ultimately culminate in the bloody insurrections under Emperor Go-Daigo.

* "Heike" is an alternate name for the Taira clan. "Gempei" is a compound of "Genji," the alternate name for the Minamoto, and Heike.