Authors: Antony Cummins
Tags: #Non-Fiction, #History, #Asia, #Japan, #Military, #Espionage
The Areas and Fortifications of the Castle
The following is a short description of the major parts of a castle and their functions. While castle technology and the story of the Japanese castle stretches way beyond this description, the basics can be found here, providing an understanding and sense of Japanese fortresses.
天守
The Tenshu
The
tenshu
is the main keep of the castle, the fortified tower at the center.
本丸
The Honmaru
The
honmaru
is the primary enclosure, which surrounds the Tenshukaku keep; sometimes the main tower can also be described as a Honmaru.
二の丸
The Nimaru
The
nimaru
is the secondary enclosure, which makes a second outer ring in the castle.
三の丸
The Sanmaru
The
sanmaru
is the third enclosure, which surrounds the castle; this can be the final wall, but castles with more enclosures did exist.
大手門
The Otemon
The
otemon
is the main gate of a castle; it is considered the primary entrance and exit.
鐘楼
The Shoro
The
shoro
is a bell tower.
矢倉
The Yagura
A
yagura
is a form of turret or building on top of a castle wall. The wall normally consists of a stone foundation and then a plaster and wooden wall on top of this foundation. On the top of this wall is a room-like building from which troops can shoot—this is the yagura turret. Shinobi manuals often talk about fire-setting skills that bring about the destruction of yagura turret houses.
石落
Ishiotoshi
An
ishiotoshi
is a section or hole where stones and rocks can be dropped. As enemy troops climb up the outside of the walls, debris is dropped on them from these relatively small areas.
逆茂木
Sakamogi
Sakamogi
are thorny branches and spiky sections that are positioned to keep invaders from attempting to infiltrate.
忍返
Shinobi-gaeshi
These are more permanent spikes that are erected along the edges of walls. They are there to keep shinobi from climbing over. However, the shinobi have various ways to deal with this issue—for example, the Bansenshukai shinobi manual says that they should be hooked with rope and ripped down.
堀
The Hori
The
hori
is the moat that surrounds the castle. Shinobi would have to measure these and wade their way across them in the dark.
馬出
The Umadashi
The
umadashi
is a fortified exit. Walls are positioned outside of the exit so that a direct charge cannot be made against it. These can be “horseshoe” shaped walls just outside of the outlet.
縄張
The Nawabari
The term
nawabari
means the overall layout of the castle, the ground plan or the birds-eye view. The term originated from stretching rope (
nawa
) used to map out the ground of a castle site.
The Japanese castle was a complex system of defense with its own kill zones and tricks to keep enemies out. In this new image of the samurai that is being built as you read, the castle must start to be seen as a complex part of samurai warfare—similar to the complexities of its Western counterpart. And of course, if there are castles, there must be sieges.
Siege Warfare
Japanese castles were adapted to siege warfare. Again the similarities between Western and Eastern warfare are evident and the sophistication of Japanese siege-craft is obvious.
If a samurai is on the defending force, the following items are things he would be familiar with as he moved in and around the castle.
Arrow and Gun Ports
Inset into the walls of castle defenses are small holes—they are normally rectangular, circular or triangular. Positioned at different heights, the defenders use them to shoot out over the field of battle. However, shinobi creep up to these apertures and fire burning arrows and flash arrows through them into the interior of the castle grounds to discover details about the interior layout. In addition to this, they would throw in hand grenades to kill those shooting out at the opposition.
Stanchions, Walkways and Shields
Along the inside of castle walls, wooden stanchions and frames would support multiple levels of walkways—similar to modern day scaffolding. Samurai would use these levels from which to shoot outward, either through arrow and gun ports or over the tops of castle battlements from between shields. In addition to this, bridges that could be retracted were set up at various positions; if the enemy breached the defenses these walkways could be retracted, allowing defending samurai to kill the enemy from the opposite side.
Killing Zones
Walls, turrets and enclosures were created to form killing grounds and zones, where the defending army could attack the enemy with crossfire and pin them into a corner and halt movement.
Turrets and Palisades
As discussed before, the castles of the early Sengoku Period and before were generally smaller; walls could be protected by turret towers, wooden shields and semipermanent buildings that were made of wood and were built along the tops of walls. Shinobi had various mixtures that would set fire to these, fires that would be difficult to extinguish, helping to break through the castle defenses.
Allied Help
A defending castle could set up a series of fire beacons and send messenger relays to request allied forces to counter the siege. Sometimes the relieving force could surround the besiegers, forcing them to defend their own rear and fight on two fronts.
Sallies and Sorties
The castle would send out night raids and attacks when they thought that the time was right. They may even evacuate a castle from an non-besieged section—if any—through gates and ports. Shinobi were trained to watch the smoke rising from castles. If the smoke from cooking fires and kitchens was too much, too little, or later than normal, a shinobi would know that the enemy had either started to evacuate or that they were preparing extra food for those going on night raids or that the food stores were diminishing. All of which was information the shinobi would pass on to his commander.
Those who were attacking the castle had certain weapons and tools to help degrade the height and protection advantages of the defenders.
Trench Warfare
Trenches at their smallest were three feet deep with an earth mound on the top of around two feet; this total of five feet covered the average height of a samurai. The closer to the castle the trench lines were the deeper they had to be dug, as arrows could be shot into the defenses from such an angle.
Towers and Constructed Turrets
As discussed previously, the enemy battle camp had collapsible turrets and towers; these were erected to see enemy troop movements and shinobi.
Battering Rams
Covered rams on wheels were used to take down castle doors and break open sections of defenses.
Shields and Walls on Wheels
Small platforms were placed on low carts with walls erected on the front. These walls had shooting ports and would be rolled into place, and from here attacking samurai could shoot at the enemy. This included walls mounted on arms that could be raised so that samurai could shoot out from below them and other such contraptions.
Shields, Bamboo Fences and Bundles
Human-sized wooden shields that stood erect with the help of a hinged single leg would protect samurai. In addition to this, bamboo was tied in large bundles and shooting ports were cut out of the middle. These bundles could be leaned against waist-height temporary fences so that samurai could shoot from behind cover.
Cannon and Fire
Cannon were used to launch fire and incendiary weapons and shot.
Kajutsu
—“the skills of fire”—included long-range rockets, flares and anything that causes flames in the enemy camp. Some shinobi were essentially agents who moved into the enemy castle and made sure that fires were set from within. One shinobi trick was to set a fire away from the main target to distract the defenders from the actual target and then to move on with their initial aim of setting fire to more important things like the main compound.
Tunneling
Tunneling was undertaken to undermine the enemy defenses. If done in secret and not on a war front, the tunnel had to start far from the target, or start from inside a nearby house. To discover if tunneling was taking place, empty barrels would be set into the ground to listen for mining below.
Moat Crossing Skills
Portable bridges and temporary structures were used to cross rivers and bridges. The shinobi’s task was to discover the length, width and depth of a moat and report the dimensions, or to cross it in secret at night.
On the whole, the samurai castle was a place of residence and the target of a siege. The samurai would defend and attack castles with ingenious tricks and tactics and shinobi on both sides would come and go, stealing information or setting fires to things, something that was quite normal in life as a samurai.