Yagura (fortress turret) (櫓 (城郭))
Yagura refers to a turret, built in a fortress, as a guard tower or a watchtower. The structure might be temporary or permanent.
Refer to yagura for hinomi-yagura turret, taiko yagura (drum turret) of a playhouse (theater), non-architectural yagura, shogi (Japanese chess) technique, etc.
Origin
According to one view, it originated from a simple watch structure.
According to another view, it originated from an armory since it was originally written as '矢倉' or '矢蔵 (arrow storehouse). '
According to another view, it originated from an armory since it was originally written as '矢倉' or '矢蔵 (arrow storehouse). ' i.e., 'a place from which one shoots an arrow.'
In the early days, it was usually a temporary structure for defensive and watching purposes to hold a castle in wartime, as seen in medieval illustrated scrolls, such as "Gosannen Kassen Ekotoba (A Scroll of the Late Three Years War)" and "Ippen Shonin Eden (Pictorial Biography of the Monk Ippen)." At the end of the Sengoku period (period of warring states), when modern fortresses started to be built, yaguras were built on the foundation stones, with tiled roofs and thick clayey walls to prevent fire and bullets. Hence, it meant to be a permanent construction. After Nobunaga ODA's conquest of the Kinki region, his vassals started to build yaguras in their castles, and such construction spread nationwide.
Azuchi-Momoyama period
From the end of the Tensho era when Hideyoshi TOYOTOMI dominated the whole country, subordinate busho (military commanders) started fortification across the nation. Especially in the castles of the western provinces, many niju (double) yaguras and hira (single) yaguras were built aside. In those days, most of them were boro-type (top tower keep placed on the main structure), which is considered an old style. No yagura of this era exists to the present, except tenshu (main keep or tower of a castle). The oldest existing yagura were built around 1601, after the Battle of Sekigahara, namely, Kumamoto-jo Castle Udo yagura and Fukuyama-jo Castle (Bingo Province) Fushimi yagura (reconstructed from Fushimi-jo Castle).
The Edo period and later
After the Battle of Sekigahara, tozama daimyos (non-hereditary feudal lords), who were transferred to other domains with substantial additional properties, built one castle after another and also reconstructed many preexisting castles. In those days, the modern fortification technique was spread nationwide with the help of Tokugawa shogunate's tenka fushin (nation wide constructions). All existing yagura were built during this era except tenshu. No one of those yaguras that were built before the Battle of Sekigahara exists to the present.
Moreover, construction of yagura was greatly advanced by the Genna era. They were usually newly developed soto (layered) type, and more functions, such as machicolation and embrasure, including newly appeared hidden embrasure, were constructed.
By the end of the Keicho era, tozama daimyos became reluctant to construct a castle out of consideration for the bakufu. Moreover, in July 1615, after the Siege of Osaka, Hidetada TOKUGAWA, the second seii taishogun, issued the Buke Shohatto (Laws for the Military Houses), which essentially prohibited construction of new castles. Then a castle was no longer built except for a few cases, such as reconstruction of Osaka-jo Castle by tenka fushin, Fukuyama-jo Castle (Bingo Province) and castles of some hereditary feudal lords, and yagura gradually became apart from the actual battles. The yagura might substitute for the tenshu of a castle that lost the tenshu, such as the Fujimi yagura in Edo-jo castle.
Although many yaguras stood in castles until the Meiji period, most of them were lost by demolition compliance with the order, fire, war and so on. Only 109 of them are left nowadays.
Structure
Compared with a tenshu, the structure of a yagura was poor in general, and thinner components were used. Therefore, a yagura lasted less time than a tenshu, and like a dozo (warehouse made of soil), its construction material was perishable since thick mud wall keep humidity. Many yaguras were rebuilt in the Edo period and original constructions hardly survived in the Meiji period.
A large-scale yagura had a main building in the center and was surrounded with an aisle called mushabashiri (warrior run). Its structure was similar to a tenshu. The yaguras that were built in a large fortress of the castles that were deeply related to the bakufu, such as Edo-jo castle, Osaka-jo Castle and Nagoya-jo Castle, had structural features, similar to a tenshu, such as a main building with several rooms. They were greater than a small-scale tenshu and had become a symbol of bakufu power.
In the small yagura built in the local fortress, there was one room and no distinction between the main building and an aisle. Many of them had one or two columns in the center of the first floor or did not have a single column in a room. Niju (double) yagura and sanju (triple) yagura might be classified into boro-type and soto-type like tenshu. The boro-type was an old style and the soto-type was new style, and appeared at the end of the Keicho era. The vast majority of existing yaguras are the soto-type. A continuous column (column which pierces the second or higher floor) is hardly used for yaguras. Usually, all columns end at the beams of the first floor.
The external appearance of yagura were usually the same design in general. Integrating materials and colors of walls, roofing and the curves of a roof, create unified beauty. At castles without a tenshu, a three-story yagura etc. was used as a substitute for the tenshu. To show the status difference from other yaguras, it was often decorated with a nageshi (a horizontal piece of timber), decorative gable, special window (kato-mado window etc.), etc. Moreover, the yagura with a special role might be decorated in a similar way.
Configuration
Sanju yagura, niju yagura and hira yagura
The yagura that has a triple, double and single roof, respectively. The number of stories might not match these.
Sumi yagura (corner tower)
The yagura located in a corner of a kuruwa (walls of a castle). Its name was usually associated with 24 directions based on its direction and location.
For example, a yagura located southeast (Tatsumi) is called 'Tatsumi Yagura.'
Tamon yagura
Tamon (多門) is a row-house-like building and it is said that it was written as "多聞" more often after Meiji period. One that was built to connect between yagura might be called watari yagura (roofed passage). Moreover, it also served as a residence. It is said that Hisahide MATSUNAGA built the first in Tamon-jo Castle.
Jubako yagura
It is a general term of the niju yagura of jubako structure; it refers to the structure whose first floor and second floor are nearly the same size. The roof of the first floor had a domer window. It is also known as a full two-story structure. This kind of yagura still remains in Okayama-jo Castle (Okayama prefecture) and Usuki-jo Castle (Oita prefecture).
Varieties by usage
Since yagura was a defensive structure, as stated in the beginning, a number of yaguras were often built in a castle, such as Osaka-jo Castle around the Edo period and Himeji-jo Castle. Therefore, they might be named, for example, Ichiban (the first) Yagura (Osaka-jo Castle) and Ino Yagura (Himeji-jo Castle). They also might be named by the direction, such as Tatsumi (southeastern) Sumi Yagura (Nagoya-jo Castle). As they also served as a storehouse, yagura where hoshiii (dried cooked rice, dry provisions) was stored might be called Hoshiii Yagura, where hatasashi-mono (battle flags) were stored might be called Hata Yagura, and where rifles were stored might be called Teppo Yagura.
In addition, some yaguras might have a specific role, such as taiko (drum) yagura. It was built on a relatively vantage point and used to sound a drum for telling the time and signaling a battle. If a bell is used instead of a drum, it was called kane yagura.
Yagura named based on the specific usage might be served for feudal lord's lifestyle and interest.
Tsukimi yagura was used for moonlight watching as its name suggested. Therefore, it usually had a relatively open structure and an extremely large opening. It was often built in the inner part of a palace or the east side of a castle. Likewise suzumi (cooling) yagura was used to enjoy the cool breeze.
Moreover, fujimi yagura was supposed to watch Mt. Fuji. Most fujimi yaguras were buillt in the Kanto region. The yagura that was the de facto tenshu was often named fujimi yagura or gosankai (three-story) yagura out of consideration for the bakufu.
Besides these, there have been numerous yaguras named in connection with their roles, configurations or origin.
Monomi yagura
A yagura was used not only for defense but for observation and surveillance. It was called monomi yagura (watchtower). Monomi yagura had been already built by the Yayoi period.
"Gishi Wajin den (first history of Japan, written in China in the third Century BC)" refers to 'rokan (turret).'
Moreover, the trace of the hottate bashira (earth fast post) structure believed to be monomi yagura has been excavated in the Yoshinogari ruins, which is thought to be the same period. Dating back to the middle of the Jomon period, from B.C. 3000 to B.C. 2000, the remains believed to be the trace of large-scale hottate bashira have been excavated at the Sannai-Maruyama site. The remains might be monomi yagura, according to one view.
In the Sengoku period (period of warring states), seiro yagura, which was a simple timber frame temporary structure, had been built. The remains of the hottate bashira structure have been excavated in the ruins of Sakasai-jo Castle and Takane-jo Castle (Totomi Province). For the same purpose, surveillance yagura have been built not only in a fortress but on the streets of Kyoto City, which was portrayed on "Ippen Shonin Eden (Pictorial biography of the monk Ippen)." Hinomi yaguras, which may be seen in a town even nowadays, are also categorized into this type. In modern times, it has been built on the foundation stone as a permanent structure of dozo-zukuri, or earthen-walled storehouse style, for the same purpose. Although tsukimi yagura (着見櫓) sounds like tsukimi yagura (月見櫓), it was used to confirm soldiers' arrival, etc. and is also known as tochaku (arrival) yagura. It served like monomi yagura for confirming the arrival of officers and soldiers. It was mostly built near the gate, etc. Likewise, Shiomi yagura had been built only in a sea castle to observe the sea.