Taiji saber, like the modern miao dao, traces its lineage to the long battlefield saber that was rediscovered by Ming Dynasty General Qi Ji Guang when he fought the Japanese pirates. On the battlefields, usually the most common weapon you have to defend against is spear. The basic tactic for long weapon against short weapon is to attack the feet of the opponent. For a short weapon, that’s the most difficult and awkward thing to do. And when you succeeded in disrupting the opponent’s footwork, you can easily attack his head or torso. That’s why the taiji dao/miao dao blade is so long – it has to be long enough to cover the feet without making you bend forward.

The guard, with its size and shape, is designed to be able to trap large weapons like the spear. The bottom portion curves inward to protect the hand. Also, in close distances, you can hold the saber the other way and use this side to trap incoming weapons as well. One common application idea is to make initial contact with the other weapon using the saber, then use your other hand to control the weapon or the opponent, while the saber, now free, is used to attack the opponent.

This saber, like Bagua Jian, is most likely designed by Liu De Kuan, along with Yang Ban Hou and Quan You, when they opened the first public martial art school in Beijing in early 1900’s. This is the reason you don’t see this dao in Chen Style.

Although light enough to be used one-handed, a lot of times, because of the weight of the saber, you need more power to generate speed at close distance, so you add the other hand. That’s where the ring comes in. Unlike in Miao Dao or Japanese sword, you don’t (in this case can’t) place the other hand at the end of the handle. Instead you hook the index and middle finger to the inside of the ring.

Because today we don’t use traditional weapons in our everyday lives, we tend to have this misunderstanding that, in order to kill, you need to swing a sword very hard. You don’t, just think about what happens when you get cut by a very sharp pocket knife. A small slicing motion with that is enough to end a life. A saber (or jian) is at least 10, 20 times bigger. When it’s sharp, adding the two fingers (plus the thumb if necessary), is enough.

Taiji saber, like the Japanese sword, is not really dao in the same way broadsword is. A broadsword, thick, heavy, with single curved edge, is a power (momentum) weapon. It kills primarily by cutting. It’s sturdy. You can use a lot of force, in both offense and defense. Its techniques tend to be simple, movements big, percussive. The traditional saying is ‘dao is like a fierce tiger’.

Jian is much lighter, more fragile. You cannot use it force-on-force directly against a heavier weapon. You have to rely on agility, finesse, quickness in changing. It’s a skill weapon. Because it’s lighter, shape more regular/symmetrical, and has more killing surfaces, its techniques more numerous and varied, more flexible, more detailed. The movements tend to be light, quick, subtle, and smooth. The traditional saying is ‘jian is like a swimming dragon’.

The taiji saber, like the Japanese katana, tries to combine the best both worlds – all the advantages of a light skill weapon (jian), with some of the power of a momentum weapon (broadsword). In this regard they mostly succeeded on the offensive side, but on the defensive side, I think both the katana and the saber are more like jian than broadsword – you still cannot do powerful, direct blocks like broadsword.

With the fall of Qing Dynasty and the rise of modern banking system (ex. carry checks instead of actual gold), the common jobs for traditional martial artists disappeared virtually overnight. So in the early 1910’s, Liu De Kuan, along with Yang Ban Hou and Quan You, joined Xu Yu Sheng in opening the very first public martial art school in Beijing. Now that they have to teach martial art to large groups of people at a time, the teaching has to be more standardized. This is when most of weapons forms for Taiji and Bagua became formally codified. It was unclear what type of dao skill Yang Lu Chan taught. But most likely his dao did not look like this one. Most people in Taiji group think this weapon was invented by Liu De Kuan at the school.

Liu was involved for many decades in security work, so he had a deep appreciation for weapons and their features. Like Qi Xing Gan, this is exactly the kind of odd, hybrid/combo weapon, full of small but extremely useful details, that only someone with his experience could invent. The addition of second edge on the back for example: it allows you to attack the opponent’s front hand directly with an upward flick, saving you the time for having to turn over to the normal edged side first.

This weapon may be rare outside Beijing, but for Northern Wu style at least, this is our standard (and only) dao. And as you can see from the official Yang Family site, it’s their standard as well.

Not to further spread misconceptions or anything, but Taiji Saber and Miao Dao are copied from Japanese Tachi (tai dao), which was in turn developed from Chinese swords imported earlier to Japan.

We don’t know exactly what the earliest use of this type of saber is, the earliest record of that dates back to 1,800 years. This type of saber appeared on battlefield very early on, but was rendered obsolete by broadswords. This is not because they’re not useful, but due to technological and manufacturing constraints. A saber is long and thin. So if the quality of workmanship is not good, it can easily shatter or break under heavy use. Chinese armies numbered in hundreds of thousands as early as 2,500 years ago. You can imagine the difficulty in supplying sabers in that quantity in a quick hurry for a principality. A broadsword, which is much more sturdy by design, is much easier to manufacture in massive quantities during wartime.

According to historian Wu Shu (late Ming, early Qing dynasty), it was last used on massive scale at the beginning of Tang Dynasty. See pictures below from Thomas Chen’s excellent site on history of Chinese swords (http://thomaschen.freewebspace.com/custom.html). Then the skills for the long sabers were lost. According to court records, as well as numerous examples from Japanese museums, this type of sword were given to Emperors of Japan as gifts.Wuyidizi on Empty Flower forum
https://chessman71.wordpress.com/2007/10/06/info-on-taiji-dao/