Sonae: the latest version of military forces in feudal Japan.


Overview of sonae

Sonae was a temporarily-formed force in the last Sengoku and the Edo periods. It consisted of several ashigaru (hired samurai) units like the archer, gun, and spear units, cavalry unit, and non-combatants engaged in logistics and military chores.

*This page is the webmaster's English translation of the Wikipedia article -- (last update date: January 28th, 2014) -- which is written in Japanese.

• History

In the periods before Sengoku, there were no structured military forces except for those formed under the ritsuryo legal system. In the following periods when the ritsuryo system ceased to work as expected, military forces were formed based on the master-subordinate relationship called 'go-on to hoko'.

In Sengoku, warlords under constant pressure to prepare for war began to form military forces or sonae that could engage in war independently by employing ashigaru soldiers in large numbers.

Sonae in the early Sengoku had no clear-cut structure, but with the rise of powerful warlords in the middle Sengoku each sonae unit came to have a specific duty to fulfill in cooperation with the mounted samurai. In the Edo period when a large-scale wartime mobilization became history, sonae came to have a fixed structure and reached perfection.

• Words and terms

**Original description is too specific for non Japanese readers to draw meaningful information. Omitted

Scale and structure

Sonae had usually 300 to 800 soldiers and the honjin (the headquarters) sonae had 1500 soldiers. The number of personnel varied depending on the fiefs of the warlord, scale of mobilization, and purpose of war. In the Edo period, regional military lords having the fief valued at more than 10,000 goku were called 'Daimyo'. The reason was that Daimyo should be able to mobilize at least one sonae force, and one sonae force was thought to require economic resources worth at least 10,000 goku.*

*The koku or goku was originally defined as a quantity of rice, weighing about 150 kilograms. A koku of rice was said to be able to feed a person for one year.

The following was a standard structure of one sonae force in the middle Edo period. This sonae led by Honda Minbuzaemon was one of the nine sonae forces formed by the Sakai family having the fief of 125,000 goku (based on the research done by Takagi Shosaku 1990).

• Standard unit or Hata-gumi

Also called standard carriers, Hata-gumi consisted of the standard officer, ashigaru carrying battle flags, the commander's standard, samurai standards, and servants.

Their role was to exhibit the position and military power of the Sakai family's sonae within and without. Although they did not take part in actual battles, Hata-gumi was a position of honor.

Breakdown: samurai(2), samurai servants(5), ashigaru(16), chugen(5), porters(4), horse keeper(1), total(33), riding horse(1), pack horse(1), total(2)

• Gun unit or Teppo-gumi

image-teppoThe unit consisted of the gun unit leader (samurai), sub-leaders and teppo ashigaru (ashigaru), and porters. The war was usually started by the exchange of arrows, which were gradually replaced by gunfire in the later periods.
The number of the gun unit members were small at first, and with time the unit grew in size so much that one sonae force had two gun units making up majority of ashigaru forces in the Edo period.

Teppo-gumi No.1 » samurai(1), samurai servants(5), ashigaru(36), porters(11), horse-keepers(2), total(55), riding horse(1), pack horses(2), total(3)

Teppo-gumi No.2 » samurai(1), samurai servants(4), ashigaru(36), porters(11), horse-keepers(2), total(54), riding horse(1), pack horses(2), total(3)

• Spear unit or Nagae-gumi

Nagae-gumi consisted of the spear unit leader (samurai), sub-leaders and nagae ashigaru (ashigaru), and porters.
Initially nagae ashigaru accounted for much of ashigaru forces, and they stood at the forefront holding up long spears (3.6 to 5.5 meters long) and fought by stabbing and beating each other.

With the increasing awareness of guns' capability and availability, Nagae-gumi gave over the starring role to Teppo-gumi and shifted their function to the protection of Teppo-gumi and the headquarters.

Since Nagae-ashigaru commanded the largest number of all soldiers, they were the first to be fired in the peace time. Even the lucky ones had to accept their position as servants like goshi or hokonin.

samurai(1), samurai servants(2), ashigaru(30), porters(3), horse keepers(2), total(38), riding horse(1), pack horses(2), total(3)

• Cavalry of Kiba-tai

Kiba-tai was a breaking force of sonae, consisting of mounted samurai (Kiba-musha) and their samurai servants.

A high-ranking retainer having an annual stipend of 1000 goku or more led Kiba-musha having annual stipends of 200 to 300, and several of them were given a leadership role to become Kumigashira (or Ban-gashira or Mono-gashira). In some cases he doubled as the commander in chief (Samurai-daisho).
The Kiba-tai guarding Daimyo in the honjin sonae was called uma-mawari, and the members were chosen from the best monted samurai warriors.

Cavalry's role was to determine or turn back the tide of battle by crashing into the fighting scenes being fought between ashigaru units which had begun to show signs of imbalance. Kiba-musha charged on horseback or got off their horses and went at the enemy on foot with their samurai servants in diverse situations.
Mostly they used spears, and occasionally used bows and guns carried by the servants.

samurai(22), samurai servants(58), total(80), riding horses(22)

• Military inspetor or Gunkan/Metsuke

Gunkan/Metsuke sent off by the superior of the commander in chief reported military exploits and breach of military rules. They were intended only for samurai, and there were other inspectors for ashigaru and low rank servants.
Much as they were annoying to leaders like the commander in chief, they were indispensable to the chain of order.

Breakdown: samurai(3), samurai servants(5), horse keeper(1), total(9), riding horses(2), pack horse(1), total(3)

• War drums and conch shells or Narimono

They were used to move the sonae units back and forth.
The sounds of war drums, conch shells, bells, and gongs moved different units according to pre-arrangement. The number of beating was not used because they were likely to be heard wrong.

Breakdown: samurai(2), porters(3), horse keeper(1), total(6), pack horse(1)

• Commander in chief or Samurai-daisho

The leader of a sonae force was called Samurai-daisho. If the army consisted of one sonae force, it was led by Daimyo himself. If there were several sonae forces, the honjin sonae was led by Daimyo, and other forces by Daimyo's senior retainers. At times, selected young samurai took the position.

Samurai-daisho was guarded by samurai soldiers on foot or by his own soldiers (called kinju). Near him stood the sonae standard flapping in the wind and in the wings waited messengers or tsukai-ban. This way, he exhibited the position and military power of his family's sonae.

Since samurai-daisho were usually high-ranking retainers having annual stipends of several thousand goku and the number of soldiers guarding him was large, those soldiers also served as a reserve force.

Breakdown: samurai(1), samurai servants(27), horse keepers(4), total(32), riding horses(2), pack horses(4), total(6)

• Archer unit or Yumi-gumi

Yumi-gumi consisted of the archer unit leader (samurai), sub-leaders and yumi ashigaru (ashigaru), and porters.
Bow and arrows or yumi had been used as the major missile until guns were used widely. They did not make any sound, had a quick-firing feature under any weather conditions, and were available at low price. And they could be used as improvised spears by fixing a spearhead at the one end. These were the features that made this weapon remain at work even if with the declining usage.

samurai(1), samurai servants(4), ashigaru(19), porters(5), horse keeper(1), total(30), riding horses(1), pack horses(1), total(2)

• Logistics unit or Konida

Konida was a supply unit consisting of the konida unit leader (samurai), sub leaders (ashigaru), drafted porters (called jinpu or bumaru) and pack horses.

Konida was arranged according to such considerations: expeditionary force or defense force, ease of local procurement (pillage or purchase), scale of mobilization, and nutritional status of draftees, etc.

Many konida leaders doubled as local administrators at the peace time. In time of war they were responsible for the procurement and distribution of various supplies for the forces on the move or in the battlefields.

Breakdown: samurai(1), samurai servants(2), ashigaru(4), porters(2), horse keeper(8), total(17), riding horse(1), pack horses(8), total(9)

Grand total: samurai(35), samurai servants(112), ashigaru(41), chugen(5), porters(39), horse keeper(22), total(354), riding horses(32), pack horses(22), total(54)


• Marching formation

The following are examples of marching formation. It was so arranged that it could rapidly evolve into the battle formation. Its details varied with different Daimyo, and the same went for the battle formation.

Standard unit - Gun unit - Spear unit - Cavalry - Samurai-daisho - Archer unit - Logistics

Standard unit - Gun unit - Archer unit - Spear unit - Samurai-daisho - Cavalry - Logistics

• Tactical formation or Jindate

When it came to the tactical formation of sonae, there were no authoritative manuals corresponding to Tercio or Maurits in the European world. Sonae's tactical formation arranged each unit laterally in a row, or in two rows, instead of arranging the units closely, and changed its configuration frequently according to the tactical situation. Most commanders seemed to follow such fundamentals that placed the ashigaru units at the first row to form the forefront and let the cavalry unit waiting behind penetrate the enemy.

Sonae's tactical formation arranged this way had higher mobility and flexibility than the European formation, enabling movement in the complex terrains, bypass operation, and quick change from order of marching to order of battle. But its frontal assault power was far less than its European counterpart.

Tactical formations like Gyorin or Kakuyoku were intended for a middle to great army, not for a force as small as sonae. Some military books in the Edo period referred to the tactical formation of sonae, but they had little practical value. It was because most of the ashigaru soldiers in Sengoku and the early Edo period were draftees who were so undertrained that they could hardly complete the formation without ruining mobility.

Fig.1 below shows the honjin (headquarters) sonae of Takeda Shingen at the battle of Kawanakjima (left) and the honjin sonae of Tokugawa Ieyasu at the battle of Sekigahara (right).


Fig.2 is a standard formation employed by many sonae forces.


Daimyo's different military power

Daimyo having a fief of more than 100,000 goku had several sonae forces which were collectively called 'te'. That meant Dai-daimyo having a fief of hundreds of thousands goku had several 'te' forces. Usually military operations were performed on the basis of one or two independent 'te' forces out of regard for the controllability by a single commander.

Fig.3 shows the army formation led by Tokugawa Ieyasu at the Odawara expedition (the formation of honjin needs reconsideration).
The Tokugawa army had the first seven 'te' forces and second seven 'te' forces, with each 'te' force consisting of several sonae forces. Each 'te' force could operate more flexibly and strategically than a single sonae force, making it an independent, practical military force in the battlefield.

The soldiers in the light blue area encircled by dotted lines were direct retainers serving Tokugawa family called hatamoto.


The number of soldiers of a 'te' force was roughly between 2,000 and 5,000, depending on the situation. 'Te' forces were formed by either gathering sonae forces of minor Daimyo or splitting a great force like that of Tokugawa Ieyasu into several 'te' forces. There were of course sonae forces which did not belong to any 'te' force and operated as single forces where relevant.

• The honjin sonae

The headquarters or honjin had two kinds of forces under its control, the fighting forces and the honjin forces. To ease the general's work load, senior retainers took control of the honjin forces at times or selected cavalry leaders in honjin led the ashigaru units of the fighting forces.

Unlike other forces, honjin included various logistic supports: engineering (diggers, earth workers and carpenters), accounting (tellers, secretaries), cooks, doctors, Buddhist monks, etc. Those support personnel were intended not only for honjin but for the fighting forces in the field. Ieyasu's honjin shown of FIg.3 had support forces for encampment and building temporary huts (not shown in the Fig)

The yoriki doshin system

When Daimyo set up several sonae forces, he delegated the command of each sonae to senior retainers except for the honjin sonae. This meant the members of the sonae forces thus arranged temporarily fell under the control of those senior retainers, but their lord to serve was Daimyo as before, not the retainers.

This is called the yoriki doshin system, and it was an effective method in organizing and commanding sonae without giving too much power to the senior retainers.