Yamagata Castle: A Flatland Castle and Mogami Stronghold in Japan
Site at a Glance
- Rating
- 4
- Popularity
- Medium
- Country
- Japan
- Primary era
- Early Modern
- External website
- Open
- Eras represented
- Early Modern, Modern
- Civilizations
- Japanese, Tokugawa
- Site type
- Military
- Remains
- Castle
On this page16 sections
History
Yamagata Castle is a Japanese flatland castle founded in 1357 during the Muromachi period, the era of the Ashikaga shogunate from roughly the fourteenth through sixteenth centuries. It stood in the southern Yamagata Basin on the alluvial fan of the Mamigasaki River, near the junction of the Ushū Kaidō highway and the route across Sasaya Pass. The site became the principal residence of the Mogami clan and later the administrative center of a large domain in Dewa.
Foundation and Mogami rule
Shiba Kaneyori, a military governor of Dewa, entered Yamagata in 1356 and established a fortified residence there. The first castle was built the following year. The Dewa branch of the Shiba family later adopted the Mogami surname, and Yamagata Castle remained the principal residence of the Mogami clan for approximately 275 years. Until the Kamakura period, the surrounding area had prospered as the center of Mogami District, giving the site an established regional setting before the castle was created.
During the Keichō era, Mogami Yoshiaki rebuilt and enlarged the castle in 1592. He added the second and third baileys, watchtowers, and a castle town. A bailey was an enclosed section of a castle, usually separated from other sections by walls, moats, or ramparts. The expanded complex became the center of Yoshiaki’s authority after he supported Tokugawa Ieyasu following the Battle of Sekigahara. Ieyasu, who founded the Tokugawa shogunate, rewarded him with a domain assessed at 570,000 koku, a unit of agricultural productivity conventionally linked to the rice needed to support one person for a year. Yamagata Castle then served as the principal castle of his enlarged territory in Dewa.
The Hasedō campaign and the name Kajō
Yamagata Castle was drawn into the conflict surrounding the Battle of Sekigahara through the Hasedō campaign. Uesugi forces commanded by Naoe Kanetsugu, a senior Uesugi retainer and military commander, invaded the region. Mogami forces repulsed the attack. A traditional explanation for the name Kajō relates that mist concealed the castle when it was viewed from the Uesugi position near Mount Togami. The castle was also known as Kasumigajō and as Yoshi-character Castle.
Tokugawa administration and decline
Mogami Yoshiaki died in 1614. Conflict among his principal retainers helped lead the Tokugawa shogunate to confiscate the Mogami domain in 1622. Torii Tadamasa subsequently altered the castle, and Yamagata and its domain passed through the hands of several daimyo families, including the Torii, Hotta, and Akimoto clans. A daimyo was a major territorial lord who governed a domain under the Tokugawa shogunate. Repeated reductions in domain revenue made the upkeep of the extensive castle increasingly difficult.
In 1767, the shogunate took direct control of the domain. Buildings in the second and third baileys were removed, and the cleared land was converted into fields. When Akimoto Ryōchō entered the domain three years later, new residences had to be built for the lord and his retainers. By the end of the Edo period, the Tokugawa shogunate’s centralized era, which lasted from the early seventeenth century to 1868, the palace stood in the second bailey, the main bailey was vacant, and farmland occupied the western half of the third bailey.
Military conversion and modern preservation
Yamagata Domain was transferred in 1870, and the han system was abolished in 1871. The long-neglected castle had already deteriorated severely. After the grounds were sold to the government in 1872, they became the barracks and compound of the Imperial Japanese Army’s 32nd Infantry Regiment. Castle towers and palace buildings were demolished, the main-bailey interior was filled, and portions of the third-bailey moats were filled and cultivated.
In 1906, returning soldiers of the 32nd Infantry Regiment planted Somei Yoshino cherry trees around the grounds to commemorate the Russo-Japanese War. The site subsequently became associated with cherry-blossom viewing. After the Second World War, the inner part of the second bailey was converted into Kajō Park, while the outer second bailey and much of the third-bailey area became urbanized. The park later incorporated the Yamagata Prefectural Museum, Yamagata City Local History Museum, a gymnasium, and a baseball field.
Yamagata Castle became a National Historic Site in 1986 and was selected as one of Japan’s 100 Fine Castles in 2006. Archaeological investigations, repairs, and reconstruction have continued. Yamagata City plans to complete investigation of the entire main bailey and reconstruct its masugata gate by 2033. A masugata gate is a defensive complex arranged around a roughly square enclosure, forcing an attacker to turn before reaching the next gate. The city also plans to relocate facilities within the second bailey and redevelop the grounds as a historic-site park.
Archaeological work in 2013 focused on the western main-bailey moat. Excavation in the former third-bailey area uncovered six pit dwellings from the Nara and Heian periods, indicating that the castle town developed over an older settlement. Two castle buildings also survive in relocated form. The former South Main Gate serves as the Sanmon gate of Banshōji Temple in Yamagata, while the main hall of Hōkō-in Temple in Yōka-machi incorporates a study hall moved from the castle palace. The latter is a prefectural cultural property.
Remains
Overall plan and setting
Yamagata Castle was organized as three concentric baileys rather than as a mountain fortress. The main bailey occupied the center, the second bailey completely surrounded it, and the much larger third bailey formed the outer enclosure. Moats, stone walls, and earthen ramparts defined the principal defensive boundaries. The Mamigasaki River originally flowed immediately north of the castle, supplying water for the moats and contributing to the outer defensive enclosure. During the Torii period, its channel was diverted to its present course.
Main bailey
Palace and central enclosure
The main bailey measured approximately 150 meters from east to west and 160 meters from north to south. It covered about 7,000 tsubo and had a perimeter of approximately 850 meters. The enclosure contained the palace, stone walls, moats, earthen ramparts, the Ichimonji Gate, and the northern Fumei Gate. Three two-story watchtowers formed part of its defensive arrangement.
The palace occupied the main bailey, whose layout included a foundation associated with a planned tenshu, the principal central tower of a Japanese castle. The completed enclosure functioned without a finished principal tower. Its moat and earthen rampart were partly filled to create the present baseball field, while planned restoration aims to recover these features and represent the palace’s full ground plan.
Ichimonji Gate complex
The masonry of the Ichimonji Gate was restored in 2004, and the bridge leading to it was reconstructed in 2006. The Korai Gate and earthen wall within the main-bailey gate complex were reconstructed in 2013 using historical-period research and were opened the following year. A Korai gate is a traditional Japanese entrance with a roofed opening and distinct structural framing. Reconstruction of these elements has drawn on late-Edo-period materials and archaeological remains.
Second bailey
Enclosure and watchtowers
The second bailey measured approximately 396 meters east to west and 427 meters north to south. It covered about 51,800 tsubo and had a perimeter of approximately 2,300 meters. Completely surrounding the main bailey, it contained the domain government offices and the Gosan-kai Yagura, a three-story substitute for a castle keep. The enclosure had one three-story watchtower and five two-story watchtowers. The former three-story tower had been demolished by the Genroku period, between 1688 and 1704.
Gates and defensive boundaries
Moats, stone walls, and earthen ramparts enclosed the second bailey. Its five gates were the first and second gates of the East Main Gate, the South Main Gate, the northern Fumei Gate, and the western Fumei Gate. The first East Main Gate incorporated a tamon-yagura, a covered tower or building set along a wall, while its second gate was a Korai gate.
The East Main Gate deteriorated seriously and was repaired in the eighteenth century. Its central section had originally been crossed by a tamon-yagura, but the damaged portion was rebuilt in reduced form between two low watchtowers. The gate was repaired and reconstructed again in 1991 on a scale comparable to the gates of Edo Castle. The water moat around present-day Kajō Park remains comparatively well preserved.
Third bailey and castle town
Outer enclosure
The third bailey formed an approximately oval enclosure measuring about 1,580 meters from east to west and 2,090 meters from north to south. It covered approximately 235 hectares and had a perimeter of about 6,500 meters. Eleven entrances served the enclosure, including the Kobashi, Kasugai, Nanokamachi, Yokomachi, Yōka-machi, Fukiage, Inari, Iizuka, Oda, Shimojō, and Sakanamachi gates.
Most of the third-bailey moats had become filled or marshy by the end of the Edo period and are now buried beneath residential areas. Excavations have nevertheless shown that substantial sections remain well preserved. The 2013 investigations in the former third-bailey area also revealed six pit dwellings dating from the Nara and Heian periods, providing physical evidence for settlement before the castle town.
Residences and urban defenses
The third bailey contained residences for 534 senior and middle-ranking Mogami retainers. Another 1,326 retainers’ residences and temples stood outside the castle around the commoner districts. Merchant houses clustered along the outer edge of the third bailey, artisan quarters occupied parts of the castle town, and a temple district east of the castle formed part of the defensive system.
Roads in the castle town radiated outward from the castle, while internal lanes included numerous bends and T-junctions. These arrangements formed the surviving framework of a planned castle town, whose residential, commercial, artisanal, and religious areas were distributed around the three-bailey complex.
