Fantasy often sports unusual weapons like the flame-bladed sword:

Flame-bladed sword | From the blog of Nicholas C. Rossis, author of science fiction, the Pearseus epic fantasy series and children's books

Source: Quora

But how historically accurate are they? Were these actually ever used in battle? And if so, why? Murphy Barrett has the answer in Quora!

Why a Flamberge?

A flame-bladed sword – aka flamberge – would certainly be effective in real combat. But would they have been more effective than a non-flame-bladed sword?

Period sources don’t suggest so. But neither do they suggest they’d be less effective. Nor does any source seem to treat them any differently than a regular sword.

So, why did people use them?

Disadvantages

Let’s start with why people might not use them.

In an actual fight, most users would have probably switched to a shorter, more manageable despatching-blade, while using the wavy sword to threaten with. You certainly wouldn’t want to plunge such a sword through someone’s abdomen. Cleaning the blade afterward would be a nightmare.

And, of course, how do you keep this monster sharp? Unless the flamberge was intended for purely decorative purposes, you still needed to wield it in battle. Going to war with a blunt sword is not exactly a recipe for longevity.

Advantages

Dealing with pikes

The flamberge, a flame-bladed zweihander, was mainly used by the Landsknecht, highly paid German mercenaries. These were the double-soldiers, mercenaries who were paid a double wage to stand in the front ranks with these swords. They would parry the pikeshafts, holding them down so that the rear ranks could advance. If anything actually broke the pikeshaft, it would more likely be a well-fed mercenary stomping on it.

The flamberge may have some advantages in dealing with pikes, for two reasons. First, the points of the serration are more likely to grip the pike rather than slide. This means the pike can be beaten down or to the side more effectively.

Second, if the pike does slide down the blade the serrations shake the shaft. If you’ve ever worked with a chainsaw or a push mower with an out-of-balance blade, you will know how hard it is to control a tool with a vibrating handle, how much extra grip force it takes, and how easily the handle can jump out of your vibration numbed hands. When you’re trying to control the spearhead on the end of a ten-foot or more length of shaft, shaking it out of your hands is an effective defense.

Cloth-cutting

A third function may be that the serrations might be more effective at cutting cloth. Much of the protection you’d see on the battlefield consisted of thick cloth in multiple layers. Even for those in extensive metal armor, there would be plenty of places where sticking a blade against a joint or drawcutting the back of a leg would be a cloth-cutting problem, not a metal cutting one.

Arresting pikes

A fourth one might have to do with a simple fact: it’s in the nature of weapons of war that their primary function is to keep the wielder alive. Killing other people is only their secondary function. Your outrageously high wage as a Landsknecht wouldn’t do you any good if you died on the battlefield.

Greatswords — when not used as a flashy spear — were most likely swung in figure-of-eights to clear halberds and pikes out of the way. They seem to have been great at enforcing your “personal space” and defending against multiple enemies at once. Against enemy pikes, the greatsword would be used to dash enemy pikes offline, a function where a wavy blade might be better at arresting another man’s weapon.

Psychology

Then, there is the psychological effect. Even if your sword is at best as effective as the plain, no-nonsense Schlachtschwerter, it does look more vicious. When an opponent sees you charge with it, they may get nervous and waver enough to offer you an opening in the pike block.

Plus, flamberges were expensive. All that ostentation and display of wealth scream, “I have been doing this for a long, long time and I have killed better fighters than you.” Which is also terrifying.

Frigging cool

This may be a good time to point out what Landsknechten actually looked like.

It was men who dressed like this:

Landsknecht with flame-bladed sword | From the blog of Nicholas C. Rossis, author of science fiction, the Pearseus epic fantasy series and children's books

Source: Quora

That’s a lot of slashed cloth and expensive dye there. And one heck of a fancy, wavy, flame-sword.

And that’s probably the main reason why flamberges were used. When considering why humans do anything that seems nonsensical, never rule out fashion. The rule of cool. The clothing signals wealth. So does the flamberge. It is the medieval German equivalent of this:

McArthur's gun | From the blog of Nicholas C. Rossis, author of science fiction, the Pearseus epic fantasy series and children's books

General McArthur’s custom sidearm. Source: Quora

It’s flashy. Ostentatious. It shows off that you make so much money, you can pay a blacksmith to wave the blade, something that doesn’t really improve its function, and does increase maintenance in the form of sharpening, but looks pretty friggin’ cool.

Never discount in your writing, “It’s cool” as a reason for human action. And if you do use a flame-sword, throw in a scene where people debate the pros and cons of doing so!