Japanese Castles 1540-1640

Japanese Castles 1540-1640

(Parte 1 de 6)


Japanese Castles 1540-1640

Stephen Turnbull • Illustrated by Peter Dennis


Introduction 4 Japanese castles in their historical context

Chronology 7

Design and development of the Japanese castle 8

The first Japanese castles • The sengoku yamashiro • The introduction of stone The development of the tower keep • Japanese castles in Korea • The use of earthworks

Elements and features of the Japanese castle 21

The overall layout • The castle wall • Bridges and gates • Castle towers • The castle keep Building a castle • The principles of defence • Mining and countermining • Catapult bombardment

The living site 40

Daily life in the castle in peacetime • The castle garrison in peacetime • The castle as palace The preparation for war • Food and water • Psychological pressures

The operational history of Japanese castles 49 Early yamashiro operations • Sengoku yamashiro operations • Operations against castles of stone

Aftermath 5 The castle town

Japanese castles today 56

Bibliography and further reading 63

Glossary 63 Index 64


The castle of Shimabara in Kyushu, a fine example of the classic style of developed Japanese castle architecture, involving the elements of a moat, the all-important huge stone bases, which are the hallmarks of a Japanese castle, and the graceful superstructure. We see here one of the corner towers, and the long white small walls pierced with gun and arrow loops.

Japanese castles as we see them today are not only final products of a long process of military evolution, but also evidence of a military revolution. In the latter half of the 16th century Japanese warfare was transformed. It changed from an activity characterised by the use of loosely organised troops wielding bows and arrows and defending largely wooden fortifications, to one that involved well-disciplined infantry units armed with guns, fighting from castles of stone. The similarities to the military revolution that was taking place in Europe at the same time are striking, but until the beginning of this period there had been no cultural contact between Japan and Europe.

Contact was made when a Portuguese ship was wrecked on the Japanese coast in 1543, and the two cultures soon began to realise how their widely separated worlds had been evolving in roughly similar ways. Both were experiencing warfare on a larger scale than ever before, which required the development of strong internal army organisation and good discipline, and both were seeing a move towards a preference for fighting on foot. Yet there were also some fascinating differences, at the same time that the European knight was giving up his lance for the pistol, the mounted samurai was abandoning his bow for a spear.

However, it is in the field of castles and fortifications that both similarities and differences are found in the greatest abundance. Italian visitors to Oda Nobunaga's castle of Azuchi in 1579 compared it favourably with any contemporary European fortress, and remarked particularly on the richness of the decorations and the strength of the stone walls. As none of these early visitors were military men, rather merchants or priests, they cannot be expected to have commented upon Japanese castles from a position of technical knowledge, but it is abundantly clear from the impression given to them by the walls of Azuchi, Osaka and Edo, all of which were enthusiastically described in contemporary Jesuit writings, that they were making comparisons with existing structures in Spain or Italy.

So what were they actually comparing the Japanese castles to? By the mid-16th century the huge sloping stone walls that surrounded Verona, Sienna or Rome had become a recognised and vital part of the townscape of a successful city. They were the defining features of the trace italienne, the fortification style characterised by the use of the angle bastion, which was designed for artillery warfare and was the most important architectural innovation since the arch. The walls of fortresses such as Osaka certainly had much in common with the European system, but what the visitors did not know was that these curiously similar structures had a completely different developmental history, were built in a completely different way, and were designed to withstand attacks of a completely different nature.

The pages that follow will offer a detailed discussion on these points, all of which went towards making the Japanese castle into a unique form of defensive architecture that acknowledged its own culture and tradition, yet responded imaginatively to changing conditions of warfare. Like those in contemporary Europe, Japanese castles experienced conflict on a huge scale when all the theory behind them was tested to destruction in half a century of fierce civil war.

Japanese castles in their historical context

By the time that the first stone walls began to appear around Japanese castles, an innovation that can be seen from about 1550 onwards, Japan had already experienced intermittent bouts of civil war for almost 1,0 years. The key to understanding the reasons for such conflicts, and the nature of the Japanese castles that arose in response to them, involves an appreciation of Japan's physical isolation from continental Asia. This protected her from some dangers, so that while China and Korea were being ravaged by the Mongol hordes in the 13th century, life was comparatively peaceful in Japan. Attempts to invade Japan were repulsed in 1274 and 1281, but this splendid isolation also meant that Japan could not expand into her neighbours' territories to acquire more cultivable land, something that Japan was desperately short of. As the struggle for land grew, the possession of military force was the best guarantor of securing new lands and of then defending them against rapacious neighbours.

The establishment of the rule of the shogun (military dictator) after the triumph of the Minamoto family in the Gempei Wars of 1180-85 provided some measure of stability amid the rivalries, but invading Mongols, rebellious emperors (who resented the purely ceremonial role forced upon their sacred office by the shogun), family leaders whose wealth rivalled that of the shogun, peasant revolts and fierce religious fanatics all played their part in disrupting the theoretical calm. In 1467 the Onin War, so called from the nengo (year period) in which it began, broke out between two rival samurai clans. Kyoto, the Japanese capital, was laid waste and among the smouldering ruins of palaces and temples lay the blackened remains of shogunal prestige. From this time on any centralised authority that was left counted for little against the naked military might of the daimyo (great names) as the rival warlords termed 5 themselves. The next century and a half is known as the Sengoku Jidai (The Warring States Period), which lasted until Japan was reunified under the Tokugawa, a process that culminated in the siege of Osaka in 1615.

Some of the sengoku daimyo had aristocratic backgrounds; others were the sons of tradesmen. Some acknowledged centuries of military tradition and service to the shogun, others learned rapidly how to swell the numbers of their armies by recruiting peasants as ambitious for advancement as they were themselves. Some ruled their territories from graceful mansions set among ancestral rice fields, but the determined ones built castles.

The castles of the early Sengoku Period looked very different from the graceful fortresses of later years. Most were just hastily constructed stockades on the tops of mountains, linked by paths and passes and looking down on vital roads. As time went by the stronger daimyo absorbed their weaker enemies and the strength of their fortified bases grew to be seen as a vital element in this process. So single stockades became fortified complexes of wooden stockades that were combined across sculpted hillsides. Then stone was added, and stout gatehouses, towers and keeps began to arise. At the same time the unexpected contact with Europe introduced firearms to Japan, so instead of seeing only ranks of archers, battlefields began to witness ranks of arquebusiers. The samurai, who had traditionally been a mounted archer, had already adopted the spear to allow him to take the fight to dismounted missile troops. Now he began to dismount from his horse to fight beside the ashigaru, the lower-class foot soldiers, in a coordinated battle plan. This was the military context that saw the birth of the classic form of the Japanese castle, a style that combined beauty with strength, and was to play a vital role in Japanese history.


1184 Fortress of Ichinotani is captured

Last recorded use of crossbows in a siege in Japan Kusunoki Masashige defends yamashiro of Akasaka 1333 Siege of yamashiro of Chihaya 1467 Onin War begins 1477 Onin War officially ends

1494 Hojo capture Odawara 1542 Siege of Toda

1543 Arrival of Europeans in Japan 1545 Night battle of Kawagoe 1549 Arquebuses used at Kajiki siege

1553 First battle of Kawanakajima 1554 Siege of Muraki - volleys of arquebuses used 1557 First siege of Moji

Capture of Inabayama (Gifu) First tower keep at Tamon 1571 Destruction of Mount Hiei by Nobunaga

1573 Death of Takeda Shingen 1574 Siege of Nagashima 1575 Siege and battle of Nagashino 1576 Building of Azuchi castle

Siege of river complex of Ishiyama Honganji Building of Maruoka castle

1578 Death of Uesugi Kenshin 1579 Siege of Miki 1580 Surrender of Ishiyama Honganji

1581 Siege of Tottori by starvation 1582 Murder of Oda Nobunaga 1584 Battles of Komaki and Nagakute - earthworks used 1586 Building of Osaka castle 1587 Invasion of Kyushu; Sword Hunt 1590 Final siege of Odawara 1591 Siege of Kunoe - unification of Japan completed 1592 First invasion of Korea 1593 Japanese withdraw from Korea 1597 Second invasion of Korea 1598 Death of Toyotomi Hideyoshi Korean War ends

1600 Battle of Sekigahara 1603 Tokugawa Ieyasu becomes shogun 1614 Winter Campaign of Osaka 1615 Summer Campaign of Osaka 1616 Death of Tokugawa Ieyasu

Design and development of the Japanese castle

The moat and part of the walls of the mighty Osaka castle, built by Toyotomi Hideyoshi in 1586. This image shows the interesting contrast between the seemingly haphazard arrangement of stones in the main sections of the walls and the neat dovetailing of fully dressed stones where the walls intersect to form exterior corners.

The first Japanese castles

The nature of the first Japanese castles illustrates another factor that arose from Japan's isolation from continental Asia - the development of a very different tradition of defensive architecture from that of China and Korea. The biggest variation lay in the almost total absence from Japan of the walled town, which was where the wealth of Ancient China was concentrated.

With no barbarian hordes to fear on their islands, the threat to Japan came mainly from internal rebels, who tended to establish themselves in purely military strongpoints. As the Japanese landscape is predominantly wooded and mountainous, it is not surprising to find these two factors combined in the design of most of Japan's earliest fortresses. A multitude of hilltop sites provided both the defensive topography and the building materials that were needed to strengthen their natural positions. The result was the development of a style of castle known as the yamashiro (mountain castle), which was to continue being built in remote areas long after the introduction of stone castles, due to reasons of convenience and availability.

For the earliest yamashiro (and for simple fortresses right throughout the period) little was done to alter the overall shape of the existing mountain or hill other than stripping the summit of enough tree cover to provide building materials and to allow good fields of view and arcs of fire. The slopes of the steeply sided hill or ridge would be allowed to retain their forested cover to prevent soil erosion and to provide another defensive barrier. Firm footpaths would be constructed linking different peaks together, thus producing a yamashiro complex that consisted simply of a number of stockaded hilltops joined to each other.

There are several illustrations of yamashiro castles in the picture scrolls of campaigns and battles fought during the Later Heian Period, from about AD 950 onwards. In all cases the landscape has been used intelligently

and economically. This leads to numerous variations of yamashiro depending on location, with great differences between those located in mountainous areas and those built in flatlands surrounded by rivers and flooded rice fields, where the castle would be referred to as a hirajiro (plain castle). A mixture of the two styles was known as hirayamajiro (a castle on mountain and plain). On the excavated hilltops there would be built quite intricate arrangements of wooden palisades, decorated wooden towers, gateways and domestic buildings. The solid wooden walls of the palisades were pierced with arrow slits, and in some cases rocks were slung by ropes through holes. In the event of an attack the rope would be cut, allowing the rocks to fall against an enemy. Towers were enclosed at the top with wooden walls or portable wooden shields, and from these vantage points archers fired longbows and crossbows, or simply threw down stones, the only other missile weapons available. Domestic buildings thatched with rice straw would also be built from wood, and acted as quarters for the garrison, reception and command areas for the general, as well as stables and stores.

The main defensive purpose of the yamashiro was to restrict a hostile forces access to an area, and also to keep his forces under surveillance. Communication between the hilltop redoubts was vital so that troops could be moved along the mountain paths from one sector to another as required. Also, if a lower section of the yamashiro complex was lost, then the overall design was supposed to permit the garrison to launch a counterattack with ease, or at the very least isolate the now hostile portion of the castle. With no stout walls like those round Chinese cities to batter down, the Japanese had no need of siege catapults, for which quite a science existed in China. Instead any siege machines used, such as large crossbows, tended to be employed in an anti-personnel role prior to an infantry assault. Thus we read of the use of oyumi (crossbows) in northern Japan that the arrows 'fell like rain', killing hundreds of samurai and causing fires, but not that they broke down any walls. This was the style of Japanese castle that played such a vital role in the Gempei Wars of 1180-85.

(Parte 1 de 6)