A wide range of battle tactics was used by samurai over nearly 700 years of medieval and early modern history. Warrior strategies in battle were determined in part by the weapons used and the topography of the battle site or domain where the campaign was conducted. In most geographical locations feasible for battle, such as open plains, cavalry were quite effective. However, Japanese topography includes inhospitable areas where archers on foot—and later, firearm units—were better suited to battles in these mountainous, heavily forested, or rocky terrains. Further, the size and degree of specialization of troops affected the military techniques employed by officers, and these factors also varied as the warriors of Japan encountered changing political and economic circumstances.
By definition, a samurai was a professional soldier and devoted hours to preparing for warfare. Battle preparations encompassed a range of activities, including mental as well as physical exercises. Warriors were encouraged to formulate a philosophy regarding death, and most retainers incorporated aspects of contemporary Buddhist and Confucian thought into their disciplined attitude toward life, danger, and death. The legendary samurai integrity essential to the code of behavior known as Bushido (literally, “the way of the warrior) derived in part from the powerful sense of personal responsibility assumed by self-reliant medieval warriors. In medieval times, retainers first drew upon their own resources to outfit and train military units, and later became dependent upon daimyo or other higher-ranking lords for support. Samurai training thus reflected the investment of a warrior’s patron or lord as well as the individual samurai’s dedication to self-improvement. Generally, during the nearly 700 years of medieval and early modern Japanese history dominated by warrior culture, samurai trained in various applied skills using the tools and principles of warfare, from basic battle maneuvers to martial strategy, and also investigated the ethical foundations of warfare.
Medieval warriors were able to train with instructor-opponents only if they had aristocratic rank or high social standing. Before the Edo peace, large numbers of peasants joined the ranks of the military in the Warring States period during the 15th and 16th centuries with little or no military background. These foot soldiers, or ashigaru, required schooling in traditional samurai mental discipline as well as intensive instruction in military maneuvers. In addition to individual exercises, foot soldiers participated in regiment drills, which endeavored to transform individual soldiers into a well-coordinated unit that operated in unison on the battlefield. In the latter part of the Muromachi and into the Azuchi-Momoyama period, foot soldiers were required to practice by following a mounted general through battle formations and attack-retreat sequences before they were permitted to pick up their weapons to fight. In the Edo period, wealthy and elite samurai participated in martial arts drills focusing on stances and motions both with and without weapons. Retainers from the warrior class alone were entitled to pursue the martial arts during the Edo period. However, such activities became more a form of sport inspired by pride in military spirit rather than true combat training, as there was no arena for combat under Tokugawa rule.
In encounters staged on open ground or slightly mountainous terrain, warriors used temporary fortifications like those discussed above. However, such building projects required significant resources, and rapid solutions were more likely to bring favorable results. In preparing for some battles, samurai armies arranged connected shields in a formation called kaidate designed for mobility. Linked wooden shields were an effective impediment to the progress of an oncoming opponent, much like temporary fortifications such as the stacked brush barriers called sakamogi, especially when conflicts took place on fields or open plateaus. Large-scale shields were more easily deployed than brush barriers, which required significant human labor and large-scale construction, and shields could be removed to another location after use. Nonetheless, both shield walls and sakamogi were vulnerable if confronted with fire, a weapon favored by early medieval warriors.
Since oyoroi armor was heavy enough to slow progress and freedom of movement, and the bows used in the early medieval period were weak, Japanese archers were forced to shoot at close range. With 10 meters or less between the archer and the target, bowmen had to carefully identify and target weaknesses in the opponent’s armor. Further, early medieval samurai horses had little endurance, especially at high speeds and while bearing heavy loads, so armies utilized light cavalry formations in which mounted archers were surrounded by small groups of infantry circling and regrouping in a manner that historian Karl F. Friday has compared to aviators in a dogfight.
Signals and Identification
As armies increased in size, especially during the Warring States period, opponents often had trouble identifying each other and commanders could not recognize important samurai amid the crush of bodies. Signals became an effective means of controlling troops from a distance during battles, since only coordinated efforts could be successful. Strategies included the use of items such as flags, drums, and conch shells, as well as deployment of fire signals and messengers. For instance, many samurai and ashigaru affixed a sashimono, or personal banner, on the back of their armor. The family crest (mon) of the army commander was usually painted on the field of the sashimono, which later developed into the more visible vertical banner called a nobori carried by standard bearers into battle. Similarly, recognizing the potential of messengers, daimyo invested in preparing elite corps of messengers. A commander relied upon his messaging system to convey orders to other generals and ensure timely compliance with directives. These messengers were specially identified by cloaks or distinctive sashimono. For example, Toyotomi Hideyoshi had 29 messengers, all of whom were fitted with a golden sashimono. Nobunaga provided his messengers with a horo, a fabric bag similar to a cloak attached to the back of the armor, in either red or black.
During the Warring States period, as the military became more professionalized and battles were plentiful, specialized signaling and other means of identifying entire companies as well as specific figures were instituted. To ensure quick identification of opposing forces at a distance or ready identification of a military leader in poor weather, high-ranking figures had elaborate helmets and other distinguishing characteristics that made them readily recognizable. At the dawning of this era of many feuding daimyo, the tradition of affixing a sashimono was abandoned, perhaps because such devices could hinder the progress of an elite warrior. Regardless, high-ranking samurai had attendants (standard-bearers) who were charged with carrying the large vertical flag known as a nobori identifying the entire company or unit.
Personalized armor or helmet elements functioned like a crest which might be etched into or painted on European armor to indicate one’s allegiance to a particular ruler. However, overall, Japanese use of banners and flags contrasted with European styles. Apparently, free-flying banners, as commonly seen in recreations of European battles, were not favored in Japan. The most typical banner style of the 15th century and after, the nobori, was a long, vertical piece of fabric that hung from the arm of a pole, which could be easily seen from both sides. Essentially these were larger versions of sashimono made more visible as well as less personal, a change that underscores the increasing grandeur of well orchestrated combat at the end of the Warring States period.
Other types of flags and banners served diverse purposes. Signal flags (as well as fires) could be employed in directing unit movements. Another banner used for identification was the uma-jirushi, or horse insignia, which was worn by the standard-bearer of a daimyo and used to determine whether a leading figure had lost his mount.
In peacetime, banners and flags served to distinguish rank and status of samurai in service to the Tokugawa shogunate. Under the reorganization of the feudal system, samurai rank was equated with banner size. For example, samurai with an income of 1,300 koku were entitled to bear a small flag, while those possessing more than 6,000 koku of annual income could display a large flag. Thus, an entourage approaching the Tokugawa castle in Edo could be identified from a distance. Such banners required three soldiers to serve as bearers, more than the single figure that had accompanied the sashimono of high-ranking retainers in the medieval period. However, due to the dearth of battles, such flags were displayed primarily during processions of daimyo to and from the capital, and represented no hindrance to the typically slow and ceremonious progress of such entourages.
Battle formations were predetermined, though once a battle began there was no requirement or expectation that the formation would be maintained. Some formations were specific to interaction among types of warriors. For example, Japanese cavalry units included both soldiers on foot and mounted samurai. In this configuration, the figures on foot served as attendants to the mounted warriors. This had a strong effect on the maneuverability of the cavalry unit, as well as the necessary charge distance the unit required.
There were numerous battle formations utilized for different strategic moments in a battle. Among the battle situations for which a specific configuration of troops might be used were formations for the initial battle charge and for subsequent charges, formations used for surrounding enemy forces, or when the two armies were of equal strength or when one army was outnumbered, various defensive formations used to maneuver against the enemy, formations used under specific terrain conditions, formations that placed a particular part of one’s army—for instance, cavalry or foot soldiers—at the front of the battle, formations for withdrawal, and formations used for a final stand against an oncoming army.
The culture of battle in the medieval and early modern periods was highly ritualized. There were, for instance, specific ceremonies enacted before going into battle and specific rituals conducted to celebrate victory. Before going into battle, it was not uncommon for prayers to be offered to the Shinto gods— such as to the war deity Hachiman—asking for divine help in securing victory. Also common was a ceremonial meal prepared prior to battle in which sake was drunk and foods with names suggesting victory were consumed, such as kachi guri, or dried chestnuts. The term kachi can also mean victory; hence, the association of “victory chestnuts” with this food. Finally, the commander would start his troops marching to battle by uttering a ritual phrase (“for glory”) while a Shinto priest said additional prayers for victory. Victory celebrations included rituals such as bathing in a hot spring both as a means of treating wounds and for purification, the presentation of letters of commendation for bravery or other heroics, and a “head inspection” in which the severed heads of the enemy taken during the battle were presented for review and particular honors were given to the warrior who had taken the first head.