Battle of Hashitayama

What Happened

On 16 September 1180, fighting broke out at Hashitayama, a hill site in the foothills of Mount Fuji. The engagement is counted among the battles of the Genpei War (源平合戦, Genpei kassen), the civil war between the Minamoto (源) and Taira (平) clans that ran from 1180 to 1185.

The sources name two men on the field: Yasuda Yoshisada (安田義定) and Matano Kagehisa (俣野景久). The battle is associated with the Kai Minamoto (甲斐源氏, Kai Genji), the branch of the Minamoto clan seated in Kai Province, the province corresponding to modern Yamanashi Prefecture.

The precise location of Mount Hashida is not settled. The site is generally placed at the northern foot of Mount Fuji, and competing theories have been put forward for the exact spot.

Background

The Battle of Hashitayama belongs to the opening year of the Genpei War. In 1180, Minamoto no Yoritomo (源頼朝), head of the Minamoto, raised arms against the Taira, who had dominated the court since their leader Taira no Kiyomori (平清盛) took power in 1160. Yoritomo's first army was destroyed at the Battle of Ishibashiyama in the eighth month of 1180, and he withdrew to the east, where the Minamoto had deep roots.

The Kai Minamoto were one of those eastern branches. Their homeland, Kai Province, sat in the mountains west of the Kantō plain, and the clan's mounted warriors made it a force in the region. The campaign of 1180 turned on which eastern houses would commit to Yoritomo and which would stay with the Taira.

The date falls in Jishō 4 (治承四年), the fourth year of the era name Jishō. The fighting at Hashitayama came in the ninth month, weeks after Ishibashiyama, as the Minamoto cause was regrouping in the east.

Why It Mattered

The engagement at Hashitayama is credited with bringing the Kai Minamoto to notice. Before 1180 the clan was a regional power in the mountains; the battle made its name part of the national contest between the Minamoto and the Taira.

The battle also belongs to the wider mobilisation of the eastern provinces in the autumn of 1180. The Taira had held the capital and the court for two decades; the war that began that year would end with their destruction at Dan-no-ura in 1185 and with the establishment of Minamoto rule. The men who fought at Hashitayama were among the eastern warriors whose allegiance decided that outcome.

The Name in Japanese

The Japanese name is 波志田山合戦, read はしたやま かっせん (Hashitayama kassen). In romaji: Hashitayama kassen.

Broken down character by character:

• 波 — read は (ha) here. The character means "wave". In this name it is used for its sound, not its meaning.
• 志 — read し (shi) here. The character means "will", "intention" or "aspiration". Again it stands for its sound.
• 田 — read た (ta) here. The character means "rice field", one of the most common elements in Japanese place names.
• 山 — read やま (yama). The character means "mountain" or "hill". It is the element that marks the site as a height, and it is the same character found in Mount Fuji's Japanese name, 富士山.
• 合 — read かっ (ka') here, the first half of 合戦. The character means "to join" or "to match".
• 戦 — read せん (sen). The character means "war" or "battle".

The last two characters together form the compound 合戦 (kassen), literally "joined battle", the standard Japanese word for a battle or engagement. The first four characters form the place name: 波志田 (Hashita) plus 山 (yama), "Mount Hashita". The spelling of the place name is phonetic rather than descriptive — 波 and 志 carry no meaning of waves or aspiration here, and only 田 and 山 read as ordinary landscape words.

Note that the name is sometimes written 波志田山 and sometimes 波志田山 with variant renderings of the first element; the reading はしたやま is the same.

Key Figures

Yasuda Yoshisada (安田義定) — a warrior of the Kai Minamoto and one of the two commanders named in connection with the battle. The Yasuda were a branch of the Kai Minamoto, and the surname recurs among the clan's fighting men in the Genpei War.

Matano Kagehisa (俣野景久) — the second commander named in connection with the engagement. He is recorded alongside Yasuda Yoshisada among the participants at Hashitayama.

Minamoto no Yoritomo (源頼朝) — head of the Minamoto and leader of the revolt against the Taira that opened the Genpei War in 1180. The battle at Hashitayama falls within the first campaign of that war, the year in which the Kai Minamoto came to wider notice.

Taira no Kiyomori (平清盛) — head of the Taira and the dominant figure at the court in 1180. The war that produced the Battle of Hashitayama was fought against his clan's hold on power.