Battle of Muroyama

What Happened

On 13 January 1184, Minamoto no Yukiie (源行家, みなもとのゆきいえ) drew up his forces at Murotsu, and the Taira army came at him in five separate divisions, one after another. The attacks were staggered rather than simultaneous: each Taira contingent struck, fell back, and made way for the next, so that Yukiie's men had no pause between engagements and no chance to rest, regroup or counter-attack. The method wore the Minamoto line down by degrees.

The commanders on the Taira side were Taira no Shigehira (平重衡, たいらのしげひら) and Taira no Tomomori (平知盛, たいらのとももり). Under the pressure of the successive assaults the Minamoto position contracted until the defenders were surrounded. Yukiie's force broke and fled the field, leaving it in Taira hands.

The engagement belongs to the Genpei War (源平合戦, げんぺいかっせん), the civil war between the Minamoto and Taira clans that ran through the 1180s. It was fought in the first year of the Genryaku era (元暦, げんりゃく), within the Heian period (平安時代, へいあんじだい), the long stretch of court-centred history that ran from 794 to 1185.

Background

The Genpei War set two warrior houses against each other for control of the country, with the imperial court as the prize both sides claimed to be protecting. The Minamoto had been crushed in the war's opening years, and the survivors fought on as scattered bands under commanders such as Yukiie, a half-brother of Minamoto no Yoritomo. The Taira, entrenched in the capital and holding the person of the child emperor, could put larger and better-supplied armies into the field.

Yukiie's campaign in the closing months of 1183 and the opening weeks of 1184 was a hard one. Muroyama belongs to that phase of the war: the Taira on the offensive, hunting down the remaining Minamoto forces in the field, while Yoritomo in the east built the military organisation that would eventually decide the war. The Taira tactic of feeding divisions into the fight in sequence was designed for exactly this kind of encounter — an enemy too strong to be swept aside in a single charge, but too small to absorb repeated blows.

Why It Mattered

Muroyama was a Taira victory, and a clean one: the Minamoto were surrounded and driven from the field. It demonstrated that the Taira could still manoeuvre and win in the field late in the war, at a point when their fortunes had begun to turn elsewhere. The five-division attack was a deliberate piece of tactics, not a brawl, and it worked.

For Yukiie it was another reverse in a career of them. He survived the battle, but his standing as an independent commander never recovered the ground it lost in this period, and he was eventually eliminated by his own side rather than by the Taira. The war itself ran on for another year and more, ending with the destruction of the Taira at sea in 1185 — the year the Heian period itself closed and the age of the warrior government began.

The Name in Japanese

The battle is written 室山の戦い and read むろやまのたたかい (muromaya no tatakai). It is built from four elements: two kanji, a possessive particle, and a final kanji with its okurigana ending.

室 — read むろ (muro) in this name. The character means "room", "chamber" or "cellar", and by extension a sheltered or enclosed place. It is a common element in place names.

山 — read やま (yama). The character means "mountain". Together, 室山 (むろやま, Muroyama) is a place name meaning something like "chamber mountain" — a name attached to the ground where the fighting took place, at Murotsu.

の — read の (no). The hiragana particle linking two nouns, here joining the place name to the word for the event. It marks possession or attribution: "the battle of Muroyama".

戦 — read たたかい (tatakai) in this word. The character means "war", "battle" or "fight". Its on-reading, used in compounds, is せん (sen), which is why the same character appears in 戦争 (せんそう, sensō, "war") and 合戦 (かっせん, kassen, "battle"). Here it takes the kun-reading and the okurigana い, which completes the native Japanese verb form 戦い, "a fight".

Note the shape of the whole: a place name, the particle の, and a noun for the event. This is the standard pattern for naming battles in Japanese, and it is worth recognising, because the same structure recurs throughout the Genpei War and every war after it.

Key Figures

Minamoto no Yukiie (源行家, みなもとのゆきいえ) — commander of the Minamoto force at Muroyama. A half-brother of Minamoto no Yoritomo, he fought a long and largely unsuccessful campaign through the western provinces in the war's middle years. At Muroyama his men were worn down by successive Taira attacks, surrounded, and put to flight.

Taira no Shigehira (平重衡, たいらのしげひら) — Taira commander at the battle, and one of the clan's most active field generals of the war.

Taira no Tomomori (平知盛, たいらのとももり) — Taira commander at the battle, and a son of the clan leader Taira no Kiyomori. He would go on to command Taira forces in the war's final engagements.