Battle of Kuisegawa

What Happened

On 20 October 1600, forces of the Western Army under Shima Sakon (島左近, しまさこん) met troops of the Eastern Army under Nakamura Kazushige (中村一氏, なかむらかずしげ) at the Kuise River (杭瀬川, くいせがわ) in Mino Province, in what is now Gifu Prefecture. The engagement was short but sharp, and it ended with the Eastern Army force withdrawing. The Western Army held the field.

The fight was a preliminary action of the Sekigahara Campaign, fought on the same day that the main armies were manoeuvring into position nearby. The result gave Ishida Mitsunari's Western Army the initial advantage in the campaign, while Tokugawa Ieyasu's Eastern Army took heavy losses in the encounter and pulled back toward Sekigahara.

Background

The battle belongs to the Azuchi–Momoyama period (1573–1603), the closing decades of the Sengoku period, the century and a half of near-continuous civil war through which regional warlords dismantled the old shogunate and fought over who would replace it. By 1600 that contest had narrowed to two coalitions. The Western Army, assembled around Ishida Mitsunari (石田三成, いしだみつなり), drew on lords loyal to the young heir of the recently dead ruler Toyotomi Hideyoshi. The Eastern Army, led by Tokugawa Ieyasu (徳川家康, とくがわいえやす), drew on lords who had thrown in with the most powerful man in the east.

The campaign that year was fought over control of the roads and castles of central Honshu. Mino Province, where the Kuise River runs, sat astride the routes that any army marching east or west had to use, and the Western Army moved to block Ieyasu's advance there. The engagement at Kuisegawa took place on 20 October 1600, in the fifth year of the Keichō era (慶長五年), as the two sides closed on one another. It was followed immediately by the Battle of Sekigahara.

Why It Mattered

Kuisegawa mattered because of what it did to the two armies' confidence and positioning on the eve of the decisive clash. The Western Army came away with the advantage; the Eastern Army came away having lost men and having fallen back toward Sekigahara. For a coalition held together by the prestige of its commander, that was a serious blow, and it shaped how the opening of the Sekigahara fighting was approached.

The battle is remembered chiefly in that frame: as the prelude that gave Ishida Mitsunari's side the better start. The advantage won at the Kuise River did not survive the next day's fighting, but the encounter stands as the moment the Western Army's campaign briefly looked to be going its way.

The Name in Japanese

The Japanese name is 杭瀬川の戦い, read in kana as くいせがわのたたかい and romanised as Kuisegawa no tatakai.

Breaking it down:

• 杭 — read here as kui. It means a stake or pile: a wooden post driven into the ground, the kind used to anchor a riverbank or a foundation. It is not a common character in everyday Japanese, and it appears mostly in compounds relating to posts, pilings and markers.
• 瀬 — read here as se. It means a shallow or a rapid: a stretch of river where the water runs fast over a shallow bed. The character is common in Japanese river and place names, and it carries the sense of moving water over stone.
• 川 — read here as gawa, the voiced form of kawa. It means river. When it follows another element in a compound, the initial k voices to g, which is why the name is Kuisegawa rather than Kuisekawa.
• の — the possessive and linking particle, written in kana rather than kanji. It joins the river name to the word for battle, so that the whole reads as "the battle of the Kuise River".
• 戦 — read here as tatakai. It means battle, fight or war. The same character appears in sensō (戦争, せんそう), war, and in senryaku (戦略, せんりゃく), strategy.
• い — the final kana, completing the reading tatakai for 戦. The verb tatakau (戦う, たたかう) means to fight, and tatakai is its noun form.

So the name is a straightforward descriptive compound: the river called Kuise, plus "battle of". The kui element, the stake or pile, suggests the river was named for pilings driven along its banks, though the name is best learned simply as a place name attached to this encounter.

Key Figures

Shima Sakon (島左近, しまさこん) commanded Western Army troops at Kuisegawa. He was a retainer of Ishida Mitsunari and one of the most respected fighting men on the Western side; his presence at the Kuise River is what gives the action its place in the campaign narrative.

Nakamura Kazushige (中村一氏, なかむらかずしげ) commanded the Eastern Army force that met Shima Sakon at the river. His troops took the heavier losses in the engagement and withdrew toward Sekigahara.

Ishida Mitsunari (石田三成, いしだみつなり) led the Western Army, the coalition whose cause the victory at Kuisegawa briefly advanced.

Tokugawa Ieyasu (徳川家康, とくがわいえやす) led the Eastern Army, whose advance the Kuise River action was meant to check.