The Nodachi/‘dachi web files
Welcome to my Nodachi/‘dachi website.
These are truly awesome weapons, but they are not just weapons - They are also art.
The definition of ‘dachi
The direct translation of "‘dachi" is big thick sword. Often mistaken for Nodachi which translates to field sword. The term Nodachi is generally misused for ‘dachi.
The character for "‘" means big or great. The characters for "DA" and "CHI" are the same as "TACHI", the older style of sword/mounts that predate the Katana (the "CHI" is the same character as Katana and the "T‘" in NihontŰ).
I think that to qualify as a ‘dachi the sword in question must have a blade length of 3 shaku (90.9 cm) or more, however, as with most terms in Japanese sword arts, there is no exact definition of the size of a ‘dachi. Generally speaking, swords that are longer than normal* ones are classified as ‘dachi.
*The normal length of swords varied slightly depending on the period. During the Edo era, the average length of a sword was about 66 - 70 cms, however during the Heian and Kamakura era it was around 80 cm. Lengths varied during different eras because the methods of use varied also. During the Heian and Kamakura era Samurai rode on horseback which required a longer blade (about 80 cm). Samurai during the Edo era didn't usually ride horses, so a shorter (about 66 -70 cm) blade was more useful.
The history of ‘dachi
It is believed that ‘dachi first appeared in the 5th Century. This has been proven by the fact that a 117.0 cm sword from the 5th Century was unearthed from an old mound in Kumamoto. A 137.9 cm sword was unearthed from a mound in Tochigi and dated to the 5th Century.
It was believed that some such swords were used by the Gods of Japanese mythology, however, most of the swords discovered so far have only dated to the 5th Century.
For example, in Japanese mythology the sword named "Hutsunomi-tamano-tsurugi" (in Kashima Shrine, Ibaraki) was believed to have been the sword that was given to the Emperor by a God to end a revolt. Now, research has show that the sword was made during the Heian era and is not the sword from the myth.
It seems the sword was an imitation piece, based on the sword used in mythology. This is the reason why some swords are believed to have been used by Gods. Another one of the reasons why people believed that the sword was used by Gods was due to the appearance of the sword. If the sword is large and awesome, it looks like the property of a God.
The purpose of ‘dachi
The purpose of ‘dachi can be categorized as follows:
a) As an offering to a Shrine or Gods. Some ‘dachi were dedicated with prayer to win a war, others were placed in Shrines as legendary swords from mythology.
b) As a weapon. From explanations in old texts, such as "Heike-monogatari, Taihei-ki" tell us that ‘dachi were used by soldiers during battles.
c) As a symbol for an army. Some ‘dachi are too long for practical use. They cannot be used in a battle but it is said that they could have been used as a symbol of an army, such as flags and spears. Further research is needed to confirm this idea.
d) As a trend during a certain period. Some swords were also used for ceremonies.
e) To show the swordsmith's skill.
NOTE: Most ‘dachi were used for reason a) and b).
The production of ‘dachi
‘dachi are very difficult to produce. The requirements to make a good ‘dachi are as follows:
a) A lot of steel is needed to produce a ‘dachi and it takes longer to make than a normal sword. However to make a good ‘dachi it is important to hammer the steel quickly. This requires great skill from the swordsmith.
b) A ‘dachi is made with teamwork. Perfect teamwork is required to make a good one.
c) More skill is required in quenching and tempering a ‘dachi than a normal sword.
d) Special facilities are required. For example the quenching tank must be bigger than that used for normal swords.
e) The method of polishing is different. ‘dachi need to be hung from the ceiling or placed in a stationary position to be polished, unlike normal swords which are moved over the polishing stones.
How to use ‘dachi
‘dachi that were used as weapons were too long for Samurai to carry on their waists like normal swords. There were two methods in which ‘dachi could be carried. One method was to carry it on your back. This was impractical however, as it was impossible for the Samurai carrying the sword to draw it quickly. The other method was simply to carry the ‘dachi by hand. The trend during the Muromachi era was for the Samurai carrying the ‘dachi to have a follower to help him draw it.
‘dachi swordplay styles focused on downward chops and different wields to that of normal swords.
The use of ‘dachi in early times
The ‘dachi's importance died off after the Osaka-Natsuno-Jin war of 1615 (battle between Ieyasu Tokugawa and Mitsunari Ishida). Since then it has been used more as a ceremonial piece.
The two main reasons for losing popularity are:
1. Battles in fields did not occur after 1615.
2. The Bakuhu government set a law which prohibited holding swords above a set length (in Genwa 3 , Kwanei 3  and Shoho2 ).
After the law was put into practice, ‘dachi were cut down to the shorter legal size. This is one of the reasons why ‘dachi are so rare.
‘dachi were no longer of practical use, but were still made as offerings to Shinto shrines. This became their main purpose. Due to the amount of skill required to make one it was considered that their awesome appearance was suitable for praying to the Gods.
The ‘dachi is no longer a practical weapon, but a few still survive to this day. Handed down from era to era as a sacred tool or treated as a legend, the sword used by the Gods in mythology. The ‘dachi has attracted many people throughout history and, hopefully, will never lose its attraction.
The majority of information presented here was obtained from the Atsuta Jingu (Nagoya) ‘dachi exhibition catalogue (no ISBN), kindly translated by H.Kakuta. Thanks to Guido Schiller for pointing out the difference between ‘dachi and Nodachi.