Before the widespread use of firearms, various kinds of plate armour were in widespread use. As muskets (and later, rifles) became widespread, full plate became less effective and fell out of use.

However, mortars and (later) cannon did exist, firing exploding shells. Unit formations would be changed depending on whether the enemy had artillery or not, because a tightly-packed formation would suffer greater casualties from a well-placed shell. Shrapnel was very much a feature of battles (named after Henry Shrapnel, of course).

With this in mind, why was body armour so rarely used? Even the most basic armour would have reduced casualties. More curiously still, effective steel helmets were replaced with caps or leather helmets such as shakos which are more decorative than protective. Steel was still relatively expensive, but not unreasonably so, and wrought iron plate was in mass production.

At the outbreak of WWI, the high number of casualties with head wounds led to swift adoption of helmets such as the Adrian helmet. Other body armour was tried as well, with varying degrees of success, but helmets were a clear win. The only innovative aspect of WWI helmets was that they were pressed from a single steel sheet which made them cheaper to manufacture. As far as their basic design went, they were functionally indistinguishable from helmets of the Middle Ages.

Failing to equip your troops to keep them alive could perhaps be understood if combat effectiveness was allowed to degrade during peacetime. However in a period covering the Napoleonic Wars, the American Civil War, and the maintenance of empires around the globe by the various European powers, this clearly is not the case.

Why did it take 100+ years for the value of effective helmets and body armour to be recognised? And how could the combined militaries of the world forget that it existed for 100+ years?

Updated following comment by Steve Bird: I've seen this question already, and I don't think it answers my question. As answers to that question say, the issue with shields is that using them effectively takes serious training. The same applies for fighting in full plate armour too - whilst I'm not a HEMA player, I'm sure it takes some practise to ignore sword strikes to your extremities and trust in your armour. This is not the case for helmets and light breastplates though - they're simple to put on, they give decent passive protection, and apart from getting used to the weight they don't affect anything else.

Also on another comment by Steve Bird, the scope may seem to be wide, but in fact it applies through the entire 19th century. Whilst the guns available are radically different, from muskets and smooth-bore cannons at the start of the century to recognisably modern rifles and artillery at the end of the century, the uniforms worn by soldiers were unchanged throughout. Headgear in particular is clearly a fashion statement and is not designed for personal protection. I'm curious why that's the case when keeping yourself alive would seem to be more of a priority - and even if keeping your troops alive is not your top priority, why anyone would start outfitting them with shakos or pith helmets (which do cost money) instead of a simple helmet.

  • Not an expert, but I'd think if you're hit by a mortar, your metal chestplate would just become a further source of shrapnel for everyone else. – T.E.D. May 23 at 13:24
  • A question along similar lines. Although it's about shields, I think the key is cost - it was cheaper to buy new men than buy all the ones you had armor. – Steve Bird May 23 at 13:25
  • @T.E.D. Mortars were not common on the european or american battle field until the 20th century.. and for most of the 1800s, most of the battle field weapons were smooth bore muskets and cannons (with a very flat trajectory) – sofa general May 23 at 14:29
  • @sofageneral - I mentioned mortars because that's what the question called out in P2 as the reason why armor would be useful. – T.E.D. May 23 at 14:34
  • This might be worth narrowing the scope since the battlefield at the start of the 1800s with muskets and muzzle-loading smoothbore cannon was very different compared to that at the end with its repeating rifles, machine guns and quickfiring, breech-loading gun-howitzers. – Steve Bird May 23 at 14:59

Looking at this slightly backwards, you could ask what are the factors that have enabled the supply of body armor to the modern infantry soldier?

Modern ballistic materials, such as kevlar, are comparatively lightweight and flexible, so armor can be manufactured in a small range of sizes and self-tailored (with straps, velcro, elastic, etc) to fit and so does little to interfere with the soldiers ability to fight. The cost of training a modern soldier is high and there is also a public expectation that the government will protect them as well as they can be protected.

A modern soldier is transported to the battlefield (by ship/plane/vehicle or combination of those) and is driven around the battlefield in an APC or flown in a helicopter, so the extra weight of their armor not a long-term factor. Modern battlefield first-aid and medical care is such that even a badly wounded soldier stands a good chance of survival, so preventing an immediately fatal wound occuring in the first place also improves the soldiers chances of returning to service.

In comparison, a rigid metal breastplate/backplate is far less practical. Getting an exact fit for each soldier would be much harder and tailoring each to its owner would be more expensive. Potentially you might be able to manufacture an adjustable metal armor but that would drive up the cost (and probably the weight too). Without a good fit it would be uncomfortable to wear and might actually interfere with soldier's movement and, therefore, their ability to fight. As the campaign progressed, the soldiers would almost certainly lose weight, which would mean that a breastplate that was a good fit when they left home becomes a loose fit after a few months in the field.

Also the 19th Century infantry soldier was literally a foot soldier, they marched to and from the battlefield (in some cases over hundreds of miles). The soldier had to carry everything they owned, their weapon(s), ammunition, uniform(s), cooking utensils, blankets, etc. Including a set of rigid armor would add both weight and encumbrance. They wouldn't want to wear the armor the whole time so it would have to be slung from the backpack in some manner.

So would there be an actual benefit to the 19th Century soldier of having this extra armor?

Studies of casualties during the Napoleonic campaigns have shown that only about 30% of the French army's fatalities at the time were from battlefield injuries. The biggest dangers to the soldier were disease and malnutrition. Body armor would provide no protection against the first and its added burden would accelerate the second.

This situation didn't change much through the century, two-thirds of the fatalities in the American Civil war were due to disease. There were similar figures for the Crimean War:

It is worth noting that the majority of deaths were not a result of combat but rather that of disease. For example, 2,755 of the British Empire’s force were killed in action compared to the 17,580 who died of disease.

On the battlefield, the majority of wounds would have been from direct fire weapons; muskets, rifles, solid shot (cannonballs, grape and cannister shot). For example, from an analysis of the injuries at the Battle of Waterloo:

There were, over the course of the four-day campaign, around 100,000 casualties to care for. About 60% of wounds were caused by small-arms from low-energy transfer injuries fired by smooth bore muzzle-loading fusils, carbines and pistols...Wounds from heavy (3–12lbs) iron round shot were usually fatal if received centrally or on the head and neck. Many limbs were avulsed by round shot. Tangential strikes by these large balls could cause severe tissue internal disruption.

There were similar figures for the American Civil war, where small arms accounted for 51.8% of battle injuries, with cannon an additional 5.7%. It's probably worth noting that bladed weapons, such as sabers and bayonets (which body armor might have provided protection against) accounted for less than one percent of these battlefield injuries.

It would have been possible to manfacture armor plate that could withstand musket and early rifle rounds but these would require thick plating that would have been unreasonably heavy for an infantry soldier. No practical armor plate would be able to stop cannon-fired shot. By comparison to the modern battlefield, in the early part of the century there was far less shrapnel (shell fragments) flying about. Early in the century there were field howitzers firing explosive shells but these were comparatively rare and their method of fusing meant that many of the fired shells were ineffective. By the end of the century, guns firing high-explosive shells were the most common form of artillery. The shrapnel from these shells would be travelling at similar velocities to rifle rounds so the armor required to stop those would be prohibitively heavy.

If a soldier was wounded, the lack of effective medical care on the battlefield and the lack of hygiene in first aid in general would mean that a soldiers chances of a return to service were low. Even a minor wound could become infected and cause the loss of a limb or even death.

...while musket balls, grape shot and sabre slashes could be lethal enough, but even superficial wounds could be fatal. Field hospitals were notoriously unhygienic and without antibiotics common infections were deadly. source

So armor that prevented a fatal chest wound might only mean that the soldier ends up dying a slower, more painful death in a field hospital. From a brutal economic point of view, it was more cost effective to have the men die on the battlefield than it was to treat the wounded and have them die later.

So if you were in charge of 19th Century army and you wanted to improve survival rates for your men, it would be far more productive to spend your money on additional food and improving heath care than on body armor.

  • Thanks Steve. There are other good answers, but I think yours is the best. My assumption was that shrapnel would be much more of an issue. If direct fire was the major factor, then that would tend to explain it. Links to back up the numbers would probably improve the answer, but this is the kind of reasoning I was looking for. – Graham May 24 at 10:45
  • If I remember correctly, direct battlefield injuries didn't surpass disease, infection, and malnutrition as causes of death until World War II. – Sean May 25 at 22:10
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    @Sean, during WWII, it depends on which parts of the war you're looking at (in Western Europe, for example, the balance was solidly towards injuries, while in Southeast Asia, it was solidly towards disease, and in the Pacific, a great many Japanese soldiers starved). – Mark May 29 at 2:15

Quality of steel was not sufficient enough to be practicable for body armor and helmets

Historically speaking, use of armor, shields and helmets declined with advance of firearms. During the Napoleonic era, they were almost completely abandoned, except in heavy cavalry units that used them to protect themselves from cold weapons (swords, sabres, spears ...) not from firearms. Helmets and to a lesser extent body armor reappeared in WW1 and latter in WW2. Helmets did offer protection against shrapnel and glancing bullets, but body armor (like for example this Soviet body armor) was only issued to specialized units (combat engineers mostly) do to it being to cumbersome and unhandy .

Now, as you can see, body armor mentioned above protected only breast, and only from submachine gun ammunition, yet it weighted 3.5 kg . Mind you, this happened in 1940's with already well developed steel technology. But in 19th century, before Bessemer process, steel was produced only sporadically with much lesser quality then after that. Contrary to that, sheer energy of muskets is comparable to modern firearms like Ak-47 and M-16 . Muskets are of course much less precise then modern weapons, but to compensate for that they were usually fired en masse and from closer range. As a consequence of that, effective body armor would have to be at least 5-6 mm thick, with corresponding weight increase, to give protection for relatively limited area.

As for helmets, note that at that time and place most of incoming fire was direct, unlike WW1 and latter. This includes artillery fire (canister shoot and cannonballs filled with gunpowder). Helmets usually protect only forehead from direct fire, and rest is dedicated to protection from overhead shrapnel and flying debris. Military caps from that area did offer some protection from direct fire, but they were mostly dedicated to stopping saber and sword cuts from above (like this bearskin capof Napoleonic Imperial Guard) . Shrapnel only became major source of combat casualties with advent of static trench warfare in WW1 . At that time, quality of steel improved sufficiently that both sides could issue various types of helmets relatively effective for stopping it .

  • An important part is also what trenches are made for. You can stand in them and have only your head peeking out while firing - so a steel helmet protects around half of the part exposed to direct fire. The helmet with the best protection during WW1, the German Stahlhelm, was 0.98 kg to 1.4 kg. If you extrapolate the same level protection (thickness etc) to armies standing upright in front of each other while shooting, you'd probably end up at something like >10 kg. – R. Schmitz May 24 at 9:35
  • The last paragraph I think is what I was looking for. I thought shrapnel would be more significant than perhaps it was. – Graham May 24 at 16:14
  • I think comparing muskets to modern rifle based on muzzle energy is too imprecise to be useful - a musket ball is far less effective at penetrating steel at the same energy than any kind of modern bullet. I think you'd have to look at some real data of muskets penetrating steel to say anything meaningful there – llama May 24 at 17:50
  • I think the rest of your answer also implies but doesn't outright state that once shrapnel became a major problem, it was mitigated more by tactics than technology - why cover your whole body in armour when you can use dirt instead, and only need to cover your head – llama May 24 at 17:53
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    @Sean Both of these were not classical trench wars, although fortifications and trenches were used . Of course, fortifications existed since time immemorial, with periods of static and mobile warfare throughout the history . – rs.29 May 25 at 22:24

Like you wrote in your question, there was a period of time when bullets and shrapnel would pierce right through armor, so there was little point in putting bulky armor on.

In addition, armor was expensive, and not easy to put on and use. This required training. By contrast, the introduction of firearms made it so that, rather than extensively train a unit of pikemen, you could give rudimentary training to new foot soldiers and send them straight to battle. So from a cost and training perspective it made little sense.

There was also a twist you might have missed which occurred when hard helmets were re-introduced during WW1: the leather strap that kept them attached were too solid. When something blew up too closely, the helmet could get caught in the pressure wave and snap your neck or worse, and that is (part of) why they were often worn unbuckled.

  • But armour wasn't expensive - that's the strange part. By the 17th century, it was cheap enough that soldiers could (and did) buy their own. By the 19th century, mass-production of iron was in full swing, and it was cheap enough that you could cover an entire ship with it, build houses and carriages with it, and so on. It doesn't take training to put on a breastplate and helmet either. As for the leather strap issue on helmets, surely again that's an issue of the military institutionally forgetting how to use armour? – Graham May 23 at 15:40
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    @Graham: Fighting in metal armor isn't something you can just do. It requires training. – Denis de Bernardy May 23 at 17:41
  • Full plate, certainly. But a helmet? Breastplate? I'm not a HEMA person, but they don't seem likely to be an issue, especially when you reckon that they would already be wearing a shako, bearskin or something like that. – Graham May 23 at 22:23

Body armor was issued to heavy cavalry. They had their horses to help carry it, and they expected to fight with saber and lance.

Cuirassiers are named for their armor.

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    Probably worth noting that their armor was intended to defend against saber and lance too. Less good against shot. – Steve Bird May 23 at 13:54
  • @o.m And yet in spite of that, they either had no head protection (just a hat) or a mostly-decorative helmet. Also that breastplate was heavy because it was intended to be bulletproof, which made it much heavier than needed to stop swords or bayonets (the intended opposition for shock troops), or to stop shrapnel. – Graham May 23 at 15:48
  • @SteveBird Is "shot" referring to cannons? I read something about later cuirasses all having a dent because the last test before they were given out was to shoot it with a musket. – R. Schmitz May 24 at 9:55
  • @R.Schmitz Yes, the example that I linked to was the hole punched by a small cannon ball. – Steve Bird May 24 at 11:20
  • There was an interesting PBS Nova series about this i saw a few months ago. They showed that gun fire could penetrate the cheaper armors but it could not penetrate the more expensive armors that the upper nobility could afford to wear. The link to the show is here: pbs.org/wgbh/nova/video/musket-v-medieval-armor – ed.hank May 24 at 14:49

Nobody forgot about armor, and it never disappeared entirely, it was simply no longer worthwhile in their particular context. Armor is expensive to produce but it is also heavy, cumbersome, and inhibits the fighting effectiveness of a soldier while not necessarily offering enough in the way of protection to justify the drawbacks.

The weight slows the speed of movement while causing soldiers to fatigue more quickly, while the cumbersome nature reducing flexibility and dexterity limits the soldier's ability to fight effectively. Heavy horse, having less concerns about weight, continued to wear some metal armor on the head and torso, but even for them armoring the extremities became more of a liability than the added protection justified. Infantrymen would not likely have been armored in the 19th century even if one ignores the cost of production, simply because the drawbacks in the field exceed the benefits. Remember that soldiers marched everywhere - having to carry 10+ kilos of metal armor around on top of all their other stuff would not be welcome, not to mention the constant maintenance required to keep iron plates in serviceable condition throughout the campaign. This simply was too great for the minimal protection offered.

Some of the information contained in this post requires additional references. Please edit to add citations to reliable sources that support the assertions made here. Unsourced material may be disputed or deleted.


It comes down to the existence of cavalry. Modern helmets are based around the assumption that soldiers are going to spread out and take advantage of whatever cover is present on the battlefield, leaving (hopefully) only their heads exposed. You can't do that if you're armed with a single-shot firearm: a cavalry charge will tear your army to pieces. Instead, infantry would be in compact formations with the mass of firepower and/or bayonets needed to repel cavalry.

Since the infantry need to be out and exposed to keep cavalry away, there's little benefit to giving them helmets and breastplates. A soldier who's lost an arm or a leg to a shell is just as much of a loss as one who's dead from a head or chest wound.

Additionally, exploding shells fired from field guns were a fairly late development: up until the 1850s, the vast majority of ammunition was either roundshot or canister. Both of these, like musket balls, carried far too much energy to be stopped by man-portable armor of the time.

A siege environment is different: one side has trenches, the other has fixed fortifications, and both sides are using mortars firing explosive shells. Helmets might have shown up here, except that helmets were expensive, while sieges were rare and usually short. It's not surprising that World War I, which was essentially a four-year siege of Germany and/or France, saw everyone start using helmets.


A lot of things happen in a century, specially the 19th.

The Industrial Revolution meant that cannons and mortars were better. You are saying that in the early 1800s [...] mortars and (later) cannon did exist, firing exploding shells. Well, I dare you to compare the effectivity of a 1800s muzzle loading cannon with any of the early WWI models. Not to mention the difference in numbers (and probably in tactics, C&C, and others).

The Industrial Revolution meant that helmets were cheaper.

The Industrial Revolution meant that a more technical approach was taken. Studies were conducted, and it was discovered the importance of head injuries, prompting many countries to switch to helmet.

And one thing that did not happen enough (at least in the last half of the XIX century) was war between industrial powers. Which meant that most militaries were not fully aware of the implications of the above points, and they did not all that they could have done to modernize their forces.

  • I agree that a lot happens in a century. :) But that "more technical approach" did not happen during the Industrial Revolution - it only happened in 1915. And the Napoleonic Wars were serious enough, covering basically the whole of Europe, that I don't understand how generals such as Napoleon, Wellington and Blucher could fail to adopt simple equipment which would give their army an edge over the other. The British Army was very serious about improving their equipment over that century in every other way - witness rifles and Maxim guns - but still no thought about helmets. – Graham May 23 at 16:58
  • Simple equipment "Simple" is in the eye of the beholder; mass producing helmets was way cheaper in the 20th century than in the 19th. And the nature of warfare changed, in Napoleonic wars troops would face artillery for a few minutes or hours usually in the open field (you would need full body armor to make a difference) while WWI Western Front troops spent days under enemy artillery fire while in trenches (the head becoming a more prominent target). Also, advances in medicine (Pasteur, u.a.) made body wounds less lethal, making head wounds proportionally worse. – SJuan76 May 23 at 20:10
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    @Graham in the Napoleonic wars, at least, they had enough trouble supplying the troops with tunics, boots, and greatcoats, never mind armour. – BittermanAndy May 23 at 22:03

You've got a lot of answers here, so rather than just adding to the noise I'm going to suggest a complementary way to look at the data. That's to look at the period in history, just as gunpowder weapons are being introduced into Europe, when armor disappears. Why did that happen? How long did it take? What are the details? This is the Nova episode hank referred to (above), although you could spend an entire academic career on it instead of an hour. It all depends how detailed you want to get.


A bit of trivia, from Colin Powell's autobiography. When he was leading South Vietnamese infantry in Vietnam they were issued a handful of new "bullet-proof" vests. As I recall he was leading a company and they only had 2 vests. So the vest was assigned to the point-man (the guy out in front of the patrol) to wear. Being in a hot jungle, on foot, they refused. And kept getting picked off by enemy snipers. Until Powell ordered it to be worn, and one soldier was saved by it - the vest stopped the bullet and he got back up after being knocked on his ass. After that the everyone wanted to wear the vest.

The US Army started issuing body armor to all soldiers after Vietnam because (a) Kevlar made it tolerably light and still effective and (b) rapid MediVac made it possible to actually save guys who suffered injuries that were not immediately fatal. The whole field of emergency medicine went through a major renaissance in the 60's and 70's, much of it driven by the US Army experience in Vietnam and vicinity. So the calculus of what was a survivable wound changed, about the same time that Kevlar and other advanced materials made body armor practical.

Also the data from Vietnam showed most wounds in that war were from shrapnel, ballistic Nylon and later Kevlar could actually stop shrapnel and many bullets, and that shrapnel injuries to limbs were survivable and "fixable" so they didn't need to be covered. Etc.

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