n May 1180 Prince Mochihito, the son of Retired emperor Go-Shirakawa, issued a statement urging the Minamoto to rise against the Taira. While Mochihito would be killed in June and Minamoto Yorimasa crushed at the Battle of the Uji, a fire had been set. In September Minamoto Yoritomo, who had received Mochihito's call from Miyoshi Yasukiyo, set about raising an army in the Province of Izu, where he had been in exile. There was an irony in the preceding events, as Taira Kiyomori had himself sown the seeds of the war, so the poetic tale goes.
His great error, we are told, had been to spare the sons of Minamoto Yoshitomo in the wake of the Heiji disturbance, allowing these three boys – Yoritomo, Noriyori, and Yoshitsune – to mature and form the leadership of a new and dangerous threat.In fact, Yoritomo's own call to arms in the east was received cautiously at best. He did manage to kill the local Taira governor, but was defeated at the Battle of Ishibashiyama by Oba Kagechika.
In the wake of this hard setback, however, Yoritomo did receive the valuable additon of Kajiwara Kagetoki to his staff. Elsewhere in the Kanto, local families began to respond to Yoritomo in varying degrees and in Shimosa and elsewhere set about eliminating Kyoto-appointed officals. This often provoked inter-province and occasionally inter-clan civil war, a common and oft-overlooked element of the Gempei War. By the Spring of the following year, Yoritomo could count on at least the tacit support of most of the notable families in the Kanto, although the Chubu, though by now nominally Minamoto dominated, existed beyond his immediate control. Yoritomo's Kanto domain is occasionally referred to as the Tôgaku, and rather then surge forward against the Taira, he contented himself for the time being with consolidating his hold locally.The Taira response to the violence was mixed and uncertain.
Kiyomori dispatched his grandson Koremori with an army eastward, but he turned back at the Fuji River in Suruga Province. Closer to home, Taira Tomomori – who would prove the most able of the Taira – had defeated the combined forces of old Minamoto Yorimasa and the warrior monks of the Miidera at the Uji River in late June. To punish the monks for their involvement thus far in the fledgling conflict, Kiyomori ordered the Miidera burned and, a few months later, a number of temples in Nara as well. While all of this was going on, Kiyomori had made the surprising decision to move the Imperial seat to Fukuhara (to the west of Kyoto) in June. His motivations for this abortive upheaval are unclear, but by the end of the year, the emperor was back in Kyoto.
In truth, the Taira seem to have settled on a containment policy as regarded Yoritomo, and made little effort following the 'Battle' of Fujigawa to reassert their control in the Kanto. They did have their hands full with other local warriors rising up, men who used the Minamoto name as a pretext for land grabs and the settling of old disputes.In the middle of 1181, Yoritomo made a surprising offer to the Taira that called for the partition of the country between the two families, with Yoritomo taking the eastern half of the country. Despite some favorable murmers from the Court, the Taira dismissed the notion out of hand. Yoritomo's offer is in any event an odd one.
He had, after all, been operating quite without concern for Kyoto since the previous summer and was at this point more or less immune to a direct Taira attack. It may well be then, as some scholars have suggested, that Yoritomo was hoping to head off the threat represented by Minamoto (Kiso) Yoshinaka. Also known as Kiso Yoshinaka (from the area of Shinano he hailed from), this rough and tumble warrior was to prove an immediate threat to the Taira – and to Yoritomo's claims of Minamoto leadership.Somewhat earlier, Yoritomo's uncle Yukiie had taken the field and was to suffer defeat at the hands of Taira Tomomori at the Battle of Sunomata in Mino Province (March 1181).
Yukkie survived this setback and would henceforth work in conjunction with Yoshinaka, who was in a better position then Yoritomo to challenge the Taira directly.In February 1181 Taira Kiyomori fell ill and died, leaving his son Munemori to rule. Later that year nature would impose a forced truce over the combatants as a poor harvest brought starvation and disease. This would last into 1183, although Yoshinaka would make some local moves in 1182. As soon as the situation improved enough for military manuevers, Munemori ordered a campaign to defeat Yoshinaka, who due to his location was more worrisome even then Yoritomo.
A host departed from Kyoto in May, and in Kaga Province split up. One force, under Tomomori, would advance to the north and swing through Noto.