Yamazaki: The Thirteen-Day Empire That Hideyoshi Stole Back

The Honnō-ji Incident gave Akechi Mitsuhide an empire. The eleven days that followed it gave Toyotomi Hideyoshi one too — and Hideyoshi kept his.

When Mitsuhide killed Nobunaga at Honnō-ji on June 21st, 1582, the four major Oda field armies were scattered. Hideyoshi was 200 kilometres west, deep in his siege of Bitchū-Takamatsu against the Mōri. Shibata Katsuie was in the snow country of Etchū. Niwa Nagahide was at Sakai with a half-formed Shikoku invasion fleet. Takigawa Kazumasu was in the Kantō. None of them was supposed to be in Kyōto for weeks. Mitsuhide had bought himself the longest possible window of unilateral action.

The Impossible March

Hideyoshi closed the window in nine days. The Chūgoku Ōgaeshi — the great westward turn-around — is one of the most-studied logistical feats in Japanese military history. Within hours of receiving word of Honnō-ji on the night of June 23rd, Hideyoshi had concluded a peace with the Mōri (without telling them about Nobunaga's death, by some accounts), turned his army of roughly 20,000 around, and begun the eastward march. He covered roughly 230 kilometres in nine days, picking up reinforcements at Himeji, Amagasaki, and Ibaraki along the way. By the time Mitsuhide grasped that Hideyoshi was already east of the Akashi River, it was too late to consolidate.

Yamazaki Ridge

The two armies met on July 2nd at Yamazaki, where the Yodo River and Mount Tennō pinch the Kyōto–Ōsaka corridor down to a defensible chokepoint. Mitsuhide's force was approximately 16,000; Hideyoshi's, augmented by Niwa Nagahide and Ikeda Tsuneoki who had ridden up from Sakai, was roughly 36,000. The decisive ground was Mount Tennō itself: whichever side held the high shoulder controlled the artillery flank. Hideyoshi's vanguard, under Nakagawa Kiyohide and Takayama Ukon, took it before Mitsuhide could move forces up. From there the Toyotomi musketeers raked the Akechi line for an hour. By dusk the centre had collapsed.

Ogurusu

Mitsuhide fled east toward Sakamoto Castle with a handful of mounted retainers. He never arrived. Tradition — recorded in Shinchō Kōki and the later Akechi Gunki — has him ambushed in a bamboo grove at Ogurusu, south of Yamashina, by armed peasants who recognized his fine armour and ran him through with bamboo spears. Whether the killing blow came from a peasant's spear or from a self-administered seppuku in the moments before, his head reached Hideyoshi's camp the next morning. The empire he had stolen lasted thirteen days from the burning of Honnō-ji. Edo writers shortened it to 'three days' for rhetorical effect, and the phrase mikka tenka — three-day rule — entered the Japanese language.

The Strategic Inheritance

Yamazaki settled more than the question of who killed Nobunaga's killer. It established Hideyoshi as the Oda inheritor in fact rather than in seniority — Shibata Katsuie, the more senior general, was now politically too late to claim the succession. The Kiyosu Conference three weeks later formalized what Yamazaki had already proven. Within a year Hideyoshi would have crushed Shibata at Shizugatake; within eight he would have unified Japan. The Oda house, paradoxically, had been preserved for someone who was not an Oda — and Mitsuhide's eleven-day window of opportunity, however cleverly seized, had been undone by an opponent who refused to accept the schedule it imposed.

"Hideyoshi has come up from Chūgoku. We will give battle tomorrow."