Battle of Shiojiritōge

What Happened

On 22 August 1548, Takeda Shingen defeated Ogasawara Nagatoki at the Battle of Shiojiritōge. The clash took place at Shiojiri Pass, also known as Katturu Pass, in what is now Nagano Prefecture. Shingen's victory removed Ogasawara Nagatoki as a serious military threat and furthered Takeda control over Shinano Province.

The battle was fought during the Sengoku period, the age of warring states, within the broader Muromachi period (1336–1573). In the Japanese calendar, the year was Tenbun 17, the era name Tenbun (天文) having begun in 1532. The engagement was one of many in Shingen's long campaign to subjugate Shinano, a mountainous province whose local lords resisted Takeda expansion for years.

Background

Shinano Province lay directly north of Takeda Shingen's home domain of Kai. Throughout the 1540s, Shingen pushed into Shinano, picking off smaller lords one by one. Ogasawara Nagatoki, a powerful shugo daimyo, or provincial military governor, controlled the northern and central parts of Shinano and saw the Takeda advance as a direct threat to his own position.

By 1548, Shingen had already taken several Shinano castles and forced alliances on other local families. Ogasawara Nagatoki gathered his forces to stop the Takeda army before it could reach his strongholds. The two armies met at Shiojiri Pass, a narrow mountain route that controlled access between the Matsumoto basin and the Suwa region. Control of the pass meant control of movement through central Shinano.

Shingen's forces won the day. The defeat broke Ogasawara Nagatoki's ability to mount a coordinated resistance, and he was forced to flee his home territories. The battle did not end Takeda ambitions in Shinano, but it removed the most organised opponent standing in the way.

Why It Mattered

The Battle of Shiojiritōge was a decisive step in Takeda Shingen's conquest of Shinano Province. With Ogasawara Nagatoki driven from the field, Shingen faced far less organised opposition in the province's central districts. Over the following years, the remaining Shinano lords either submitted to Takeda authority or were crushed individually.

The victory also cemented Shingen's reputation as one of the Sengoku period's most capable commanders. His ability to defeat a provincial governor in his own territory, at a defensible mountain pass, demonstrated both tactical skill and strategic patience. The battle contributed to the consolidation of the Takeda domain, which at its height controlled Kai, Shinano, and parts of neighbouring provinces.

For Ogasawara Nagatoki, the battle marked the beginning of the end. He never recovered his former standing and spent the rest of his life in exile or under the protection of other lords. The Takeda advance into Shinano continued after Shiojiritōge, and by the early 1550s Shingen had effectively made the province part of his own domain.

The Name in Japanese

The Japanese name for this battle is 塩尻峠の戦い, read in kana as しおじりとうげのたたかい. In romaji, it is Shiojiritōge no Tatakai. The name translates roughly as "Battle of Shiojiri Pass," with 塩尻 (Shiojiri) being the place name, 峠 (tōge) meaning "mountain pass," and の (no) a possessive particle.

Breaking down the characters:

• 塩 (shio) — "salt." This character appears in the place name Shiojiri. In this word it is read しお (shio).
• 尻 (jiri) — "buttocks" or, by extension, "lower end" or "foot" of something. In this word it is read じり (jiri). Together with 塩, it forms the place name 塩尻 (Shiojiri), which likely refers to a location at the lower end of a salt-trading route.
• 峠 (tōge) — "mountain pass" or "ridge." This character is read とうげ (tōge) in this word. It is a Japanese-made character, combining 山 (mountain) with 上 (up) and 下 (down), reflecting the idea of a road that goes up one side of a mountain and down the other.
• の (no) — a possessive or attributive particle, equivalent to "of" or "'s" in English. It links the place name to the noun that follows.
• 戦い (tatakai) — "battle" or "fight." This is read たたかい (tatakai). The character 戦 carries the meaning of war or combat.

So 塩尻峠の戦い breaks down as "Shiojiri Pass's Battle" or, more naturally, "The Battle of Shiojiri Pass." The place name Shiojiri itself survives today as a city in Nagano Prefecture, near the site of the battle.

Key Figures

Takeda Shingen (武田信玄) was the head of the Takeda clan and the daimyo of Kai Province. Born in 1521, he spent much of his life expanding his territory through military campaigns, most notably into Shinano Province. At Shiojiritōge, he commanded the victorious Takeda forces. Shingen is remembered as one of the most formidable warlords of the Sengoku period, and his rivalry with Uesugi Kenshin to the north became legendary.

Ogasawara Nagatoki (小笠原長時) was a shugo daimyo who controlled large parts of Shinano Province. He led the forces that met Shingen at Shiojiri Pass and lost. After the defeat, Nagatoki's power collapsed, and he was forced to abandon his territories. He later sought refuge with other warlords but never regained his former position. The Ogasawara family, however, survived and continued as a minor house into later centuries.