I was sent the following article by my good friend Alex Meehan in Ireland last night and felt that it was very informational and would benefit a larger audience.  Please take a few minutes to read the following article on the history and evolution of the tachi and Japanese sword.  It is not surprising that Soke was making recent reference to the differences of the Japanese sword and the relevant periods and this nice little essay can provide for excellent insight.









What is a tachi?

By Alex Meehan

 Hatsumi Sensei has said that in 2010 we will be looking at the Japanese tachi as part of our study of kenjutsu, as well as the idea of ‘Rokkon Shojo’. But just what is a tachi? Most people will know it’s a kind of Japanese sword, but is a tachi different from a katana? If it is, how?

The short answer is that a katana is a medium length sword designed to be worn with the edge oriented up in the belt. It’s fast, extremely sharp and can be drawn in a single flowing movement from the belt. It is primarily used with a two handed grip and unlike western swords it was rarely if ever partnered with a shield – in essence the katana is used to both attack and defend with at the same time and it functions as both a weapon and shield in one.

 The katana first appeared and started to gain mass adoption by the warrior classes in Japan in the Momoyama period (1568 to 1603) and continued to be used and worn by the samurai class up until the Meiji restoration in the late 1860s. It was often paired with a shorter sword, known as a wakizashi to make a daisho set, the iconic signature twin swords of the samurai.

By contrast, the tachi is an older style of Japanese sword, popular in Japan from the end of the Heian period (794 to 1185) right through the Kamakura period (1185 to 1333) and up to the end of the Muromachi period (1568 to 1603). These earlier swords were typically more curved than the later katana, were often longer and were usually housed in mounts designed to allow the weapon to be worn edge down, slung from the belt.


Historically, tachi were a high class weapon made to be used by people who could expect to fight in armour on a battlefield. The curvature of the blade and the fact that they could be used with one hand meant they could be used from horseback if necessary. Such a weapon was normally worn paired with a kodachi (small tachi) or tanto (dagger), a shorter blade used for up close fighting and grappling, or a yoroidoshi, a special style of dagger used specifically for use against an armoured opponent.

 It’s generally accepted that the word tachi stems from the term tachikiru, which means to ‘cleave in two,’ but depending on how the characters are written in Japanese, it can also mean ‘great sword’ or ‘horizontal sword,’ possibly because the blade tends to be slung horizontally from the belt of someone wearing armour.

 However it’s useful to know that the word tachi can refer to both the design of a blade or to the mounts used to house a blade.

 Tachi-koshirae, which is the name for the slung-edge-down-armoured-mounts that most people understand by the term tachi, is really just a suit of clothes for a sword. Historically it was common for people wealthy enough to have a new sword commissioned and made especially for them to have several different interchangeable koshirae for their blades – one for wearing to war, one for wearing around town, etc – in accordance with their social position and means.

 (What those different koshirae looked like varied a lot throughout history with different styles of mounts going in and out of fashion, but that’s a different subject really.) So it’s possible to distinguish between the style of mounts a sword is housed in and the actual blade within.

Tachi through the ages

It wasn’t uncommon for tachi to be passed down through the generations, getting refurbished along the way to fit the times. For many samurai, it was much cheaper to have an existing sword altered than it would have been to have a new one made from scratch. Getting a sword made by a decent smith could cost as much as a full year’s salary, but a new set of mounts and a repair job for an older sword was much less expensive.

There are also other reasons why an old sword might be refurbished. Even if a samurai had the money to have a new sword made for them, it could also be the case that a family sword was considered blessed with a lucky spirit resident inside. If a sword had been used in a notable victory by someone’s great grandfather and had been handed down from father to son, then perhaps the kami would look favourably on the great grandson as well if he used the family tachi?

 In this way, many tachi were effectively turned into katana by being shortened and having new mounts made for them to fit the fashion of the day. As time passed, the tachi evolved into the uchi-gatana and then into the katana (these are more or less the same thing), getting progressively shorter and more manageable as time went on.

 From tachi to uchigatana to katana

As battles became less common after the warring states period ended, the samurai class were still expected to wear daisho (long and short swords) as part of their everyday dress. Carrying a huge sword around would have been a pain, but a katana could be easily thrust through the belt, worn with the tsuka angled up and the saya down so as not to get in the way.

 It’s interesting to consider that people wore swords this way for their entire lives, not just while fighting but while going about their day to day business. For them, carrying a sword in tachi mounts would have been a serious hassle.

 The history I’ve just outlined here is just that, an outline. There are lots of exceptions in this stuff and I’ve really only written about generalities. For example, in general we can say that tachi are longer, heavier and more curved than katana and that they come in special mounts that allow them to be worn edge down slung from the belt. But you should also know that there are lots of exceptions to this rule.

For example, at various points in Japanese history it was possible to find a tachi blade housed in katana mounts, and during the crossover period when both tachi and katana were in use, it was conceivably possible to find katana in tachi mounts.

Sometimes tachi were longer and more curved but sometimes they weren’t. Sometimes they started out large and over time were cut down and remounted to make them shorter, and sometimes they were made short. It’s a case by case thing.

In actual fact, telling a tachi from a katana can be quite difficult. I’ve asked several really expert people in Japan about this and the best advice I’ve had is that the only reliable way to be sure whether a blade is a tachi or a katana is to take the tsuka off and see which side of the nakago (tang) was signed by the smith who made it.

Japanese swords have an ura and omote, an inside and outside, and they were almost always signed on the omote side with the smiths name. How can you tell which is the omote side?

The omote is the side of the nakago that faces away from the person wearing the sword, and it will of course be different depending on whether a blade was made to be worn edge up or edge down. It’s easy to see whether the smith who made the weapon intended it to be a tachi or a katana based on which side of the tang he signed.

This is why you’ll sometimes some blades displayed edge up and some edge down if you visit a museum with a sword exhibition – they’re displaying the blades the way the smith intended the sword to be worn. Even with this though, there can be problems – some smiths signed their blade on the inside rather than the outside, just to be different.

By focusing on tachi, Hatsumi Soke is taking us back to a very old period of Japanese history. I’ve no doubt that 2010 will be an extremely interesting year.


It’s worth remembering that martial artists make notoriously bad historians and that a rank in the Bujinkan Dojo in no way qualifies anyone to be an authority on history – what you’ve read here is a just a general overview. I strongly encourage people who find this subject interesting to research this stuff yourselves – a good place to start is with The Craft of the Japanese Sword, written by Leon and Hiroko Kapp with Yoshindo Yoshihara, or with The Japanese Sword, a Comprehensive Guide by Kanzan Sato, both published by Kodansha.