learn/[id]

ERA

8 min read

衣

ERA

Kinugasa Castle and the Death of Miura Yoshiaki: How an 89-Year-Old Commander's Self-Sacrifice Enabled Yoritomo's Entry into Kamakura

Kinugasa Castle is where Miura Yoshiaki died at age eighty-nine in 1180, after ordering his son Yoshizumi and the clan to escape to Yoritomo while remaining himself as rearguard. This article verifies the historical basis of the loyalty legend and examines the castle ruins preserved as a historic site in Yokosuka.

| Samurai History

Contents

MOKUJI

1

The Miura Clan's Main Base

›

2

The Battle of Kinugasa

›

3

Kinugasa Castle Ruins Today

›

4

The Historical Significance of Yoshiaki's Sacrifice

›

5

Related Spots to Visit

›

6

Frequently Asked Questions

›

Minamoto no Yoritomo, whose escape route to Boso was secured by Miura Yoshiaki's sacrifice, enabling his later entry into Kamakura

Wikimedia Commons / Public Domain

The ruins of Kinugasa Castle stand on the hills of Kinugasa-cho in Yokosuka. This medieval mountain castle served as the main base of the Miura clan on the Miura Peninsula. In the eighth month of 1180, Miura Yoshiaki — eighty-nine years old — held this castle against the forces of Hatakeyama Shigetada until he could hold it no longer, sacrificing himself so that his son Yoshizumi and the rest of the clan could escape to join Yoritomo. This decision preserved the chain of events that led to Yoritomo’s entry into Kamakura and the founding of the shogunate.

The Miura Clan’s Main Base

The Miura Peninsula thrusts south from Sagami Province, flanked by Sagami Bay and the mouth of the Sagami River. Controlling the peninsula meant controlling the maritime route between Boso and Kamakura. The Miura clan had been based here since the late Heian period, combining naval and land forces. Kinugasa Castle was built on a plateau of Mt. Kinugasa, its surrounding terrain providing natural defensive lines.

Hatakeyama Shigetada, who besieged Kinugasa Castle against Miura Yoshiaki — later celebrated as the model warrior of Bando

Wikimedia Commons / Public Domain

The Battle of Kinugasa

After Yoritomo’s defeat at Ishibashiyama on the twenty-third day of the eighth month of 1180, he fled by sea to the Boso Peninsula. Yoshiaki held Kinugasa Castle as a rearguard action for Yoritomo’s cause. But Hatakeyama Shigetada, fighting on the Taira side, led a large force to besiege the castle. With the outcome a foregone conclusion, Yoshiaki ordered his sons to escape and join Yoritomo: “I will die here; you must live and serve Lord Yoritomo.” This is the account in the Azuma Kagami.

Whether this was purely heroic self-sacrifice or also reflected the practical reality that an eighty-nine-year-old could not realistically escape, the Azuma Kagami emphasizes the heroic dimension. What is not in doubt is the result: Yoshizumi and the others escaped to Nuttajo Castle and then by sea to join Yoritomo in Boso.

Hojo Masako, the spiritual pillar of the shogunate who stood beside Yoritomo in the 1180 campaign for eastern Japan

Wikimedia Commons / Public Domain

Kinugasa Castle Ruins Today

Kinugasa Castle is designated a historic site by Yokosuka City. The ruins — accessible by a thirty-minute walk from JR Kinugasa Station — retain earthworks, terraces, and dry moats typical of medieval Japanese mountain castles. On clear days the castle offers views toward Tokyo Bay, allowing visitors to visualize the maritime routes the Miura clan controlled.

Hojo Yoshitoki, the second regent who formed the Council of Thirteen alongside Miura Yoshizumi

Wikimedia Commons / Public Domain

The Historical Significance of Yoshiaki’s Sacrifice

Yoshiaki’s death was the immediate fall of the castle. But his sacrifice bought Yoshizumi time to escape, and Yoshizumi’s joining of Yoritomo in Boso contributed to Yoritomo’s recovery. Yoritomo then entered Kamakura and built the shogunate. Yoshizumi was selected as one of the Thirteen Lords after Yoritomo’s death — the continuity of Miura loyalty from Yoshiaki through Yoshizumi underpinned the clan’s consistent importance in the shogunate.

Shomyoji Temple (Kanazawa Ward, Yokohama), a Kamakura-period temple that inherited the warrior faith of the Miura Peninsula

Wikimedia Commons / Public Domain

Related Spots to Visit

•

Kinugasa Castle (Yokosuka) — The castle where Miura Yoshiaki died at eighty-nine

•

Nuttajo Castle Ruins (Yokosuka) — The naval base from which Yoshizumi escaped by sea

•

Tsurugaoka Hachimangu (Kamakura) — Spiritual center established by Yoritomo after entering Kamakura

•

Hatakeyama Shigetada Commemorative Park (Yokohama) — Later fate of the commander who besieged Kinugasa

•

Shomyoji Temple (Kanazawa Ward, Yokohama) — Historic temple of the eastern warrior tradition

Frequently Asked Questions

Why did Miura Yoshiaki not flee?

Both the practical impossibility of escape for an eighty-nine-year-old and the strategic choice to buy time for the clan’s escape are plausible. The Azuma Kagami records the heroic dimension, but both possibilities merit consideration.

When was Kinugasa Castle abandoned?

It fell out of use when the Miura clan declined and was destroyed during the Meio era (c.1492–1501). It functioned as the Miura clan’s stronghold throughout the medieval period.

What happened to Hatakeyama Shigetada after he besieged Kinugasa?

He later joined Yoritomo’s side and became a core retainer of the shogunate, before being killed by Hojo Tokimasa’s forces at Futamatagawa in 1205 (see Hatakeyama Shigetada Commemorative Park).

How do you access Kinugasa Castle ruins by public transport?

Approximately thirty minutes on foot from JR Kinugasa Station. The route includes mountain paths; hiking footwear is recommended.

Last updated: May 22, 2026

── END ──

Taketoki（たけとき）

Samurai History

Toku editorial team — samurai history. Insists on primary sources and castle-layout diagrams, walking battlefields from Yoritomo's Izu exile sites to the late-Edo battlegrounds.

This article was

♡ Helpful

⤴

詣

Visit Related Places

History truly comes alive when you visit in person. Choose your next destination from the related sites and pilgrimage courses below.

1. Kinugasa Castle

The Miura clan's stronghold where Yoshiaki died at 89 enabling Yoritomo's entry into Kamakura — a medieval mountain castle embodying Miura loyalty

2. Nutta Castle Ruins

The Miura naval base at Nutta Castle — after Kinugasa Castle fell in 1180, Miura Yoshizumi retreated here and escaped by ship to join Yoritomo in Awa, a pivotal moment for the Kamakura shogunate's founding.

3. Hatakeyama Shigetada Historic Park

National Historic Site marking where Hatakeyama Shigetada — 'the mirror of Bando warriors' — was ambushed and killed by Hojo Tokimasa's forces at Futamatagawa in 1205

Pure Land garden and Kanazawa Bunko library of the Hojo clan

Pilgrimage Course

Japan Top 100: Kanto

Pilgrimage Course

Yokohama Kanazawa History Walk

Related Articles

共通のスポット

Nuttajo Castle Ruins and Miura Yoshizumi: The 1180 Maritime Escape After the Fall of Kinugasa That Enabled the Kamakura Shogunate's Founding

Nuttajo Castle served as the naval base from which Miura Yoshizumi escaped by sea to join Yoritomo i

共通のスポット

Hatakeyama Shigetada and the Battle of Futamatagawa: The 1205 Conspiracy That Killed the Model Warrior of Bando

In the sixth month of 1205, Hatakeyama Shigetada was killed at Futamatagawa in Musashi Province thro

共通のスポット

Kajiwarayama Park and Kajiwara Kagetoki's Last Stand: The 1200 Destruction of Yoritomo's Trusted Vassal in Suruga Province

In the first month of 1200, the expelled Kajiwara Kagetoki and his kinsmen were destroyed at Mt. Kaj

I C H I G O I C H I E

Explore pilgrimage with the app

View in app

✕