Philippo Vadi's instructions for the size of your sword, in Chapter 2 of his De Arte Gladiatoria Dimicandi, are the earliest example of sword specs in fencing literature. So what is Vadi Sword Geometry?

He says (as I translate it in The Art of Sword Fighting in Earnest):

Chapter II: The Measure of the Two-Handed Sword

The sword should be of the correct size,

The pommel should come under the arm

As it appears here in my writing.

As you wish to avoid any trouble,

The pommel should be round to fit in the closed fist

Do this not to enter the trap.

And may this be always done:

The handle should be always a span

Who does not have this measure will be defeated.

So your mind is not deceived,

The crossguard should be as long as the handle

And pommel together, and you won’t be doomed.

The crossguard should be strong and square as needed

With a wide and pointed iron,

It must cut and thrust to do its duty.

Take note and understand this addendum

If you wish to test the sword in armour,

Make the cutting edges four fingers from the point,

With the handle as is said above,

With pointed crossguard, and note well the text.

He also says (in Chapter 1) that:

If you wish to truly know

If fencing is an art or science

Hark my words, I say.

Ponder this, my statement:

It is a true science and not an art

And Geometry, which divides and separates,

By infinite numbers and measures

And fills her papers with science,

Shows this with its pithy eloquence.

So when I met Peter Johnsson at the Helsinki Knife Fair in 2017 and he told me about his theory about medieval sword designers using geometry to create the proportions of the sword, it struck a nerve. Peter's theory has been published in his article Righteousness is Quadrangular, and he has a related blog post here.

Peter's method can be taken to extraordinary (and I think probably unhistorical) lengths, with every little bit of the sword somehow geometrically designed. But I wouldn't be at all surprised to find that his basic theory is right. It's a very simple and elegant way to create a basic sword design. As we know, size matters when it comes to swords…

Here's my simplified approach, using just nine circles. To follow along you'll need a piece of paper, a straight edge, a pair of compasses, and a pencil.

Step One:

Draw a straight line:

Step Two:

Draw five identical circles that just touch each other, with a pair of compasses. The centre of each circle is on the line.

Step Three: 

Draw four more circles, the same size as the previous, with the point of your compasses on the point where the previous circles touch.

[You could do these nine circles in one step, just placing the point of the compasses on the point where the circle you have just drawn cuts the line]

Step Four:

Mark the line for the crossguard, by drawing a line perpendicular to the original line, at the point where the first circle cuts the line. Then draw in the crossguard.

Step Five:

Draw the blade. This version has the right length, but is clearly too wide at the hilt. The width is determined by the points where the crossguard bisects the third circle (counted from the right).

Step Six:

Draw the rest of the sword. I adjusted the width of the blade at the crossguard to be the same as at the fifth intersection of the circles up the blade, then let the point taper from there. I just sketched the handle and pommel as I pleased.

Step Seven

Colour it in and share it with your friends!

I made the blade green because that's the colour of Luke's lightsaber in The Return of the Jedi, my first Star Wars movie.

Some things should be apparent from this post.

1. I will do anything to please my readers. Within reason…
2. I really do not know how to draw. This is why I hire people…
3. I'm not much good at photography either.
4. I am a sword geek.
5. Editing is really hard, and I will procrastinate in all sorts of ways…

But, there you have it: applying Peter Johnsson's sword geometry theories to Vadi's sword proportions. You can see the man himself doing it in this rather cool video:

For more in-depth discussion of the academic side of Vadi's sword proportions, see The Art of Sword Fighting in Earnest.

Choosing a Sword

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