Realistically, how useful would a bayonet be on a crossbow in medieval, close quarters combat?

Question

Historically, there's about a 700-year gap between when crossbows start appearing in European texts around 950, and when bayonets do the same around 1670. And those bayonets are strictly associated with muskets, as sources note the change from plug bayonets to socket bayonets over the next 30 to 40 years. Modern crossbows usually have a cocking stirrup at the front instead of a blade.

The lack of historical overlap and/or association hasn't stopped fantasy settings from putting bayonets on crossbows. Apparently there's a rule for it for D&D 3.5 in Complete Scoundrel, and several fantasy images popped up in my search.

But how effective would this actually be? If a target armed with a sword managed to close the distance, how well would the archer be able to defend themselves with just a bayonet attached to a crossbow?

---

https://en.wikipedia.org/wiki/Complete_Scoundrel

This one looks like a photo of a fantasy prop:

And this is a crossbow that's designed to be carried in a sword sheath. Not exactly the same thing, but close.

https://www.pinterest.com/pin/AQkXWXg76_rGUYO6uZ0XUicufGir8FDjQVMDlQf_MK4RJwKQ5H9fJ2c/

Answer 1

Former Marine, I carried and was routinely trained with bayonets for years. Here's my input:

Crossbow bayonets are not very effective. The bayonet was adapted due to the preceding pike and gun tactic. Half your guys had pikes, half had guns. The problem was that not only does this mean half your guys can't carry guns, but if the pikemen should falter or run you lose all of your musketeers to understandably angry enemy infantry venting their frustrations on their formerly unassailable adversaries. Muskets were very long, 6 to 7 feet, attaching a bayonet meant that instead of needing pikemen you can now have 100% of your men armed with guns, but still be capable of closing ranks and repelling cavalry with their bayonets. Bayonets combined pikemen and musketeers, and was so effective it essentially ended melee only infantry types within a short time of its implementation.

The bayonet was useful against swordsmen due primarily to the large (by melee standards) amount of standoff distance it created when fixed to a musket. Crossbows are shorter by nature of requiring a heavy prod (proper terminology for the bow part of a crossbow) to be cocked without breaking. These prods provide an excellent handle for the swordsman to rip it out of your hands, and crossbows were only 1/3rd as long as muskets with bayonets attached, no such standoff distance is gained by attaching a bayonet. Not to mention that this prod is quite unwieldy and makes bayonet maneuvers difficult to impossible.

The bayonet on a musket keeps the swordsman farther out of reach of a sword, and the musket itself adds another very important layer of uncertainty for the swordsman. The swordsman can't be certain that his target doesn't have a loaded weapon and is simply waiting to get him close enough that his death is guaranteed. A crossbow has a very obvious indicator that it is not loaded, as it will not have a bolt strung.

So crossbow bayonets are not very useful weapons in my humble opinion. Hell, bayonets in general aren't very useful anymore either except as a tool for aggression training and physical conditioning.

Answer 2

It is interesting that the crossbow and the pike are in fact the complementary weapons of the "Infantry Revolution", both weapons allowing relatively untrained men (with the proper tactics) to effectively take to the field against highly trained knights and men at arms.

Understanding why these are complementary weapons also explains why a bayonet was never mounted on a crossbow in real life.

The mass of pikemen in a square presented a forest of blades which was difficult for mounted or dismounted fighters to penetrate. it is essentially defensive in nature, (pikes are set to repel charges and prevent dismounted men from penetrating the line), although highly trained men who are capable of moving together as a unit and aggressively led can use pikes offensively (as leaders from Alexander III to the Swiss confederacy well knew).

Modern re-enactors demonstrate a pike square

Crossbows allowed men with limited training to effectively shoot projectiles at armoured knights and men at arms, and in great numbers. Longbows and recurve bows as used by the English and Ottomans could be as effective as crossbows, but required far more training to use effectively than a crossbow, and in the case of recurve bows were also difficult and expensive to make due to the use of multiple materials, glues and careful setting and drying/curing times. Crossbows ultimately provided much more striking power as well, a spanned steel crossbow could have a draw weight of 1200 lbs / 600kg (far more than any unaided man could provide) and deliver a quarrel with lethal force even against an armoured opponent.

Crossbowman in the late Middle Ages

So the crossbowman can shoot quarrels capable of dealing death and injury to even armoured knights, but has a slow rate of fire due to the need to span the bow. The pike square is essentially defensive, but provides the "stand off" distance to prevent knights and men at arms form closing with the troops. The ideal combination (and this was carried on even into the gunpowder age) was to mass blocks of pikemen and put the missile armed troops in between the blocks of pikes.

Although this is a diagram from the age of "shot and pike", substituting crossbows for the arquebuses gives you the idea

Crossbows by themselves are far too short to provide the "stand off distance" needed to protect yourself from a mounted man, and you would be well within the reach of anyone with a sword, pole arm or even a mace or war hammer to effectively defend yourself, unless you had extensive training (which of course defeats the entire notion of the Infantry Revolution in the first place). A crossbow on a stock long enough to effectively act as a "pike" when the bayonet was mounted would likely be too unwieldy to use effectively (the weight of the bow arms on the front of such a long stock would make it difficult to aim, and running forward to place the spanning mechanism on the bowstring would reduce the rate of fire even more).

So short answer is "no", a bayonet would not be very effective on a crossbow. If if comes to blows, the bowman could start swinging the bow, or drop it and pull a long knife. Of course if it really does come to that, it means the pike square has collapsed and your side is pretty much done anyway.....

Answer 3

It might work.... but carrying a short sword or other stand-alone hand-to-hand melee weapon would probably work better.

The cross bars/arms may make wielding your "pig sticker on a stick" harder. Any foot loop used for cocking it could be problematic, or at least reduce the effective length of the blade. Any windlass mechanism may be over sensitive to damage, or end up with strings/rope/cable swinging around causing a tripping hazard.

Consider that the bayonet fixed to the end of a long barrel gun is really a way to let a soldier fire a shot or three, and then become a pike man or a spear man to keep other soldiers at a distance or to engage mounted enemies. Early firearms were fairly long - and VERY long rifles were popular throughout the age of bolt actions, the Mosin-Nagant (developed 1890/91) is 48 inches long and has a bayonet that extends that another 2 feet. I don't think a crossbow comes anywhere near to that over all length, which would reduce the efficiency of the bayonet.

So... possible, if the engineering challenges are over come (windlass, etc. and foot loop). But probably unlikely due to unwieldiness, lack of length, etc.

Edit after question was edited - Definitely plausible - after all someone who is being attacked will use anything at hand to defend themselves. How well it might work is still going to be dependent on a few things- 1 - How does the bayonet attach? If on a pivot point (like Mosin-Nagant, the SKS, etc) or carried in a sheath and locked into place when needed to be used? If carried in a sheath, depending on design it may serve quite well as a short sword/big knife. Draw and fix, or draw, drop crossbow, and engage in hand to hand?

I still think that having it attached to the crossbow will be problematic due to the bow arms - plenty of basic training bayonet exercises on youtube, as well as historical stuff regarding early muzzle loaders (British redcoats, etc) - might be worth a watch to see how a mounted bayonet is used and then decide for yourself if the bow arms are an issue.

Answer 4

First, to reload a decently powerful crossbow, you need a stirrup to have enough strength. It might not be practical to attach a bayonet.

Second, a bayonet is basically a dagger, and daggers do not do well against things like plate armor. Daggers only do well against armor in very close combat or to finish off someone by stabbing armor weakpoints or by having specialised daggers like Rondel daggers to stab through mail or other soft armor more easily. By attaching a dagger to a crossbow, you lose the agility and manoeuvrability a dagger has.

Third, why attach a dagger to your crossbow if you can have a more handy backup sword? It's like attaching and underslung 9mm single shooter under a rifle when you can have a semi-auto pistol as backup.

Fourth, it makes you crossbow more unwieldy. You have more weight on the front so less stable shot, your weapon is longer which might be a bad thing in close quarters, in corridors or tight spaces.

Fifth, there are usually melee units to "take the aggro" for you as a crossbowman. Therefore, it is very rare when you have to use melee yourself, making the bayonet kind of a gimmick.

Sixth, unlike with a backup sword, you can hardly parry any attack. You can still somehow block with your crossbow, but it would likely be damaged or unusable after a while.

Seventh, you lack any reach to be intimidating. Muskets and rifles are pretty long (especially muskets). This makes them usable as spears, albeit kind of short ones, but they are still somewhat viable to keep an enemy at a certain distance. A crossbow being pretty short, you just cannot have enough reach to be intimidating. I think you would barely have the reach of a longsword, but without the agility or the parrying abilities.

Eighth, your opponent can easily break your "guard". Many medieval techniques strike the opponent's weapon to set it aside, breaking the opponent's guard, and then strike at the now vulnerable opponent. Due to the nature of the crossbow, and opponent can do this both horizontally (as you would do against other weapons) and vertically (by striking on the bow itself and potentially disarming you or breaking your weapon).

Answer 5

On a close range combat, having a bayonet is for sure better, for self defense purposes, than having just your hands and maybe remembering some prayers.

How much better of course depends on two parameters:

• defenders' vs attackers' amount of training
• tactical set up of the defense

Effectively use any weapon, especially in medieval time, required years of intensive dedication. Train to use two different weapons such as crossbow and sword would have roughly doubled this time.

Therefore I think on paper it could work, in reality it was too resource intensive, that's why it was not widely used. Also, a dead sword trained archer is a double loss for the defending army.

Answer 6

I would say that it is just as easy to just draw a sidearm (like a knife) in a pinch. For more info I would recommend this video by NUSensei: https://youtu.be/jxHTZ1fVHMA

It is about sudden melee scenario's when using a normal bow and not a crossbow, but I think it still applies.

Answer 7

Probably not, the crossbow is so wide at the tip that it would be easy for your opponent to block it. If not totally, then enough to shift the blow off centre making it miss and or lose most of it's force. Not to mention the expensive mechanism is going to be at the front of the combat letting your attacker grab it and pull you or your weapon into their lines.

Bayonets are really a two handed weapon, grips on rifles/crossows are designed for being pulled into your body not being pressed out like a sword. To use this the crossbowman would have to give up his pavis (if he had one).

This might be more practical for the Chinese repeater crossbow as that is quite short range and you could be suddenly in a melee. But I would think that the blade should be on the back of the bow, maybe like an axe tucked under the firer's arm so the draw mechanism is not fouling the strikes.

Answer 8

Not very useful for a standard crossbow and a standard bayonet. However if designed as a unified weapon system it might have potential. The enormous draw weight of steel crossbows is a way of making the horizontal crossbow more compact without losing power, something a vertical longbow does using length. The whole cocking mechanism of a crossbow make a bayonet awkward. Have to think outside of the box. A butterfly knife type bayonet pivoting underneath the crossbow stock on a locking keyhole pivot post at the end of the stock. Out of the way until needed. A quick flip opens the blade for bayonet use and a twist disengages the blade and handle for independent short sword use.

Cocking the bow itself would require a different approach. The bow would be held in a slide on the stock. Cocking is a two stage process. First pull the bow back to cock the string on the trigger. The Qin trigger lock is best since it automatically locks when the bowstring is pulled into it. Then set the front of the stock on the ground and step in the belly of the bow and push down with your body weight until the bow slider locks in a slot. I've thought of several slider-lock mechanisms that would be well within the ability of a medieval blacksmith. I'm really surprised that no crossbows except perhaps the Gastrophetes use body weight to cock it. Soldiers would weigh at least 150 lbs with armor. Why not use that weight?

Far easier to train with than a traditional longbow. And using it as vertical crossbow allows far tighter masses of soldiers. So how effective would it be? Well it's better than nothing which is what both crossbowmen and archers had when it came to up close and personal. Some training in new tactics would be essential. And if the enemy tries to grab the bow pushing forward on the stock slides the bayonet blade straight into him.

Answer 9

If you look at the Italian crossbow guilds, their weapons are in between 4 to 5 feet as actual Medieval European designs weren’t as short as popularly depicted. The Chinese designed a different much shorter trigger with a smaller lever and in their armament inventories are often full with lots of crossbows and swordstaffs, making it the common combination of their forces, similar to Skandinavia depicted below. A bayonett doesn't have to be a dagger, but can quite well be a light short spear. This is a weapon type associated with mounted crossbowmen. So 4 feet bow with a 4 feet spear gives 8 feet of a half pike and with 10 feet you have a Morris pike used in naval warfare by the marines for millenia, although the way European crossbows were operated allows for a longer spear of 6-7 feet and a common naval pike of 11-12 feet.

Dolnstein depicting a battle between Landsknecht pike from Germany against crossbow and swords taff native to Skandinavia. Unlike muskets, the crossbows aren't depicted firing volleys more than one rank deep. The swordstaff is an 8 feet long hewing spear.

This article on mounted crossbowmen shows their use in conjunction with lancers. The lance was a disposable weapon due to the likelihood of damage, so presumably units could switch and there are reports of light lancers with crossbows from the Balkan, North Africa and the Iberian peninsula, who previously used javelins instead of crossbows. Creating a weapon capable of switching is probably more expensive than creating both types of weapons separately and switching on demand to a streamlined efficient design.

If you look through Liechtenauer's treatise on mounted combat, you find fights between crossbowmen and lanceurs, where the crossbow prod is used to deflect the lance and use the release of the bolt as a variable length spear. A crossbowman might have considered his weapon superior to a spear, leading to the situation depicted by Dolnstein, linked above.