How Dong Haichuan Invented the Moon Knives in Baguazhang

At Dragon Phoenix, the Moon Knives are one of the most unique weapons in Cheng Style Baguazhang. They are also called Deer Horn Knives, Crescent Moon Knives, Mandarin Duck Axes, or Double Moon Knives. Unlike the spear, straight sword, or broadsword, which are found in many Chinese martial arts, the Moon Knives are especially connected to Baguazhang itself.

Traditionally, the invention of the Moon Knives is attributed to Dong Haichuan, the founder or first public transmitter of Baguazhang. Like many stories from the early history of Chinese martial arts, the details are difficult to prove with complete certainty. But the tradition is meaningful because the weapon fits Baguazhang so well that it is hard to imagine it belonging anywhere else.

Dong Haichuan is widely credited as the founder of Baguazhang, and most existing Baguazhang schools trace their lineages back to him. Some teachers describe him more carefully as the first person to publicly transmit Baguazhang, because there are older stories connecting the art to Taoist circle walking and private training methods. Either way, Dong stands at the beginning of Baguazhang as we know it today.

A Weapon Made for Baguazhang

The Moon Knives are not ordinary short blades. Each weapon is made from curved crescent shapes that cross through the center, creating several points, hooks, and cutting surfaces. They are usually trained in pairs, one in each hand. Because of this shape, they can cut, hook, trap, jam, redirect, press, and control.

This is why they fit Baguazhang so naturally.

Baguazhang is based on circle walking, turning, changing direction, entering from angles, and moving around force instead of meeting it directly. The Moon Knives do the same thing in weapon form. They are circular weapons for a circular martial art.

General descriptions of Deer Horn Knives note that they are especially associated with Baguazhang and are used for trapping weapons, disarming, close combat, and fighting against longer weapons such as spears, swords, and broadswords.

That is exactly the kind of problem Baguazhang is designed to solve. How do you close distance safely? How do you move off the line? How do you enter without crashing into force? How do you control the opponent’s weapon while changing position?

The Moon Knives answer these questions in the language of Baguazhang.

Why Dong Haichuan Would Have Created Them

The traditional idea that Dong Haichuan invented the Moon Knives makes sense when we look at the needs of Baguazhang fighting.

Dong Haichuan lived in a time when martial arts were not just hobbies. Weapons mattered. A martial artist needed to understand distance, timing, concealment, and how to deal with longer weapons. The Moon Knives are short enough to be carried close to the body, but complex enough to deal with a wide range of attacks.

Because they are held in both hands, they also match the paired-hand nature of many Baguazhang palm changes. One hand can cover or trap while the other strikes or cuts. One hand can redirect while the body turns. One hand can open the door while the other enters.

This is very different from simply swinging a sword. The Moon Knives are not about standing at a distance and exchanging cuts. They are about entering, turning, wrapping, and controlling.

That is why the weapon feels like it was born from Baguazhang movement.

From the Palm to the Blade

One way to understand Dong Haichuan’s invention of the Moon Knives is to see them as an extension of the palm.

In empty-hand Baguazhang, the palm does many things. It can strike, redirect, press, hook, lead, cover, or control. The palm is not just a hand position. It is a method of expressing whole-body movement.

The Moon Knives take those same actions and give them edges, hooks, and points.

A wrapping palm becomes a hooking action.
A changing palm becomes a cut.
A covering palm becomes a weapon trap.
A turning step becomes an entry.
A waist turn becomes a disarm or uprooting action.

This is one reason the Moon Knives should not be learned as separate from Baguazhang. Without the body method, the weapon becomes awkward. With the body method, the weapon becomes alive.

The Name: From Axes to Moons

The Moon Knives have gone through several names over time. One older name is often given as Ziwu Yuanyang Yue, sometimes translated as Meridian Mandarin Duck Axes. Another name is Yuanyang Yue, or Mandarin Duck Axes, emphasizing that the weapons are used as a matched pair.

They are also commonly called Lu Jiao Dao, or Deer Horn Knives, because the curved points resemble antlers. In English, many people call them Crescent Moon Knives because of their shape.

In Cheng Baguazhang, Moon Knives or Double Moon Knives has become the preferred name.

This name carries a beautiful play on words. In Mandarin, Shuang Yue can be heard in two ways. The character 钺, pronounced yuè, means axe or battle axe. So Shuang Yue can mean Double Axes. But 月, also pronounced yuè, means moon. So the same sound can also suggest Double Moons.

Because the weapons look like phases of the moon crossing through each other, the moon meaning has become especially fitting in Cheng Baguazhang. The name is practical, poetic, and visually accurate.

This is very much in the spirit of Chinese martial arts, where a name can carry function, image, and meaning at the same time.

A Weapon for Changing

The Moon Knives are sometimes misunderstood because of their unusual shape. People may look at them and wonder if they are practical. But the shape makes sense when we understand Baguazhang.

The weapon is not designed only for chopping. It is designed for changing.

The hooks can catch.
The curves can redirect.
The points can threaten several directions.
The paired use can control and attack at the same time.
The circular shape supports circular movement.

This makes the Moon Knives especially useful against longer weapons. A spear or sword has reach, but once the Baguazhang practitioner closes the distance and changes the angle, the Moon Knives can jam, trap, or control the longer weapon. They are not meant to win by reach. They are meant to win by footwork, timing, and angle.

That is pure Baguazhang.

Why the Tradition Matters

Whether we can prove every detail of Dong Haichuan’s invention historically is less important than understanding why the tradition has survived.

The Moon Knives express the heart of Baguazhang. They are circular, paired, deceptive, practical, and difficult to use without proper body training. They require the same qualities the empty-hand art requires: stepping, turning, coordination, relaxation, structure, and change.

This is why they are so closely connected to Dong Haichuan in Baguazhang tradition. He is remembered as the source of the art, and the Moon Knives are remembered as a weapon that expresses the art in metal.

At Dragon Phoenix, this is how the Moon Knives are understood. They are not just exotic weapons. They are part of the Cheng Baguazhang system and an extension of the same principles found in circle walking, palm changes, applications, and forms.

Learning the Moon Knives at Dragon Phoenix

At Dragon Phoenix, students first develop the empty-hand foundation of Cheng Baguazhang before moving into weapons. This is important because the weapon should grow out of the body method. The student must first learn how to step, turn, change, and move from the waist. Then the weapon can extend those skills.

The Moon Knives are one of the clearest examples of why Baguazhang weapons are not separate from Baguazhang practice. They teach the student how to carry the circle into the hands. They show how a palm can become a blade, how a hook can become a trap, and how a turn can become an entry.

If Dong Haichuan created the Moon Knives, he created a weapon that perfectly matched the art he passed down. If the tradition is partly legendary, it still points to something true: the Moon Knives belong to Baguazhang because they move like Baguazhang.

They are double axes.
They are double moons.
They are the circle made into a weapon.

And in Cheng Baguazhang, that makes them one of the most meaningful weapons a student can study.