This is one thing I've always been curious about. There were centuries of musket warfare, and even into early rifles and breech loaders. But it's always depicted as the two sides standing 100yards away and firing at each other. I have a vague knowledge of different tactical advancements like fire by ranks, platoon fire, and oblique tactics. But I was curious what I was missing and if there are any game changers. Like it just doesn't make a lot of sense to me for a force that knows it's smaller to put professional troops immediately in harm's way. There might be a macro concept I'm missing, but any info about the key advancements in musket warfare would make my day!
The problem is that way too much attention is paid to line infantry and even then too much attention paid to their use of muskets. In reality nor musketry nor line infantry alone paint an accurate, complete picture of warfare in the early modern period. First of all there's the fact that melee combat had never stopped being an expected feature of war, the pike squares of the 16-17th centuries were for much of the period the majority of infantry, and they didn't really dissapear because they were no longer useful, they just gave way to the bayonet of the 18th century, in order to combine musket firepower and the pike into one soldier. So the 18th century line infantry soldier often gets confused for light infantry which causes people to think they were fighting in a rather ineffective manner, but they were fighting in the same types of formations as the pikemen of old, or like roman legions or greek phalanxes, that is as heavy infantry, with the added benefit of integrated firepower support because their pike poles can shoot out lead balls. So while firefights could and did occur and could be very lengthy and bloody, they served a support role to the eventual bayonet charge, and the balance between both weapons varied, sometimes only a few volleys would be exchanged before one side gave way, sometimes a formation would approach the enemy, fire a single volley at very close ranges, and then proceed to charge, sometimes they wouldn't even shoot at all and go straight for the charge. The notion that two armies would just stand there and shoot mindlessly was the ideal that armies of the day sought to achieve, of disciplined, unflinching firepower to overwhelm the enemy, but it remained just that, an ideal, and musketry was actually mostly a hectic, disorganized, chaotic affair of anxious, frightened troops, which on its own could hardly be decisive, thus melee combat never really lost its relevance, which really makes 18th century warfare more similar to medieval than modern combat, which is often the frame of reference that people have since muskets are the predecessors of our modern weaponry.
More important is the development of light infantry tactics which is often overlooked. The technical limitations of the day established a sort of tradeoff, you can either have greater rate of fire at short ranges with a smoothbore musket loaded with a ball of smaller diameter, or greater accuracy with a tight fitting ball and a rifled musket at the expense of rate of fire. While the first is excellent for heavy infantry combat in which short ranges are to be expected anyways, the second is better fit for a different set of skills and tactics, and as such light infantry often fought in open order formations in broken terrain, relying not on force of numbers but on individual initiative and marksmamship, and they would often be deployed ahead of the main army to harrass enemy formations and snipe officers and drummers to sow confusion among enemy lines, plus engaging in smaller scale operations ouside the battelfield such as raids, ambushes, skirmishes, and was especially useful in sieges where the rate of fire was not really a pressing issue, which is very significant in itself given the absolute ubiquity of sieges over any other kind of military operation during the period. The complications of loading a rifled musket and its greater cost though meant that the smoothbore musket was overrepresented in the battlefield, but it doesn't tell the whole story.
Then there's the fact that infantry was not alone in the battlefield, it also had to face off against cavalry and artillery, the former of which was a threat to the flanks and rear and could exploit any gaps in a disorganized formation, and the latter of which could be absolutely destructive against a dense infantry column or square. So infantry did not just statically fire volleys at other infantry, it had to weather murderous cannon fire as it approached the enemy before coming within musket range and had to quickly form up in squares to fend off incoming cavalry, and was of course also supported in its operations by its own cavalry and artillery arms, whether in the offense or the defense. Both cavalry and artillery have their own histories of tactical and technolgical development during the early modern period that played a fundamental role in shaping the overall conduct of war in the battlefield along with the development of musket infantry. In short there was an entire very complex and highly developed tactical system in which the musket was but one single weapon, even if the most common, and even so only by the 18th century.
As i talked about sieges above i think it needs some greater explanation because the art of siege warfare suffered a dramatic transformation during the period due to the influence of firearms, for the traditional fortifications of medieval times were ill suited to resist the destructive fire of the new siege guns, so fortification architecture developed to be able to better resist cannon fire as well as to be able to emplace guns itself for defense. Arsenals of fortifications included all sorts of guns of all sorts of calibers for defense, and this significantly included large numbers of garrison troops armed with muskets to shoot over the walls, through musket loops, from the covered ways or in trenches, ditches or whatever other makeshift fortifications to aid in the defense. Musket fire was essential both by attackers and defenders during the assault made on a breach made by cannon fire or in an attempt to climb over the walls. Heavily fortified fronts such as the Netherlands, Italy, Livonia or the Balkans were the stage for long drawn out wars of sieges and countersieges in which the demand for musket armed infantry was significant.
In strictly technological terms the musket was the big advancement in itself, for once proper handheld firearms with a wooden stock and a firing mechanisn were developed in the late 15th century it hardly changed at all for the next 300 years, sure there were several incremental improvements later on, the most significant of which being the universal adoption of the more reliable flintlock but also including paper cartidges, lighter barrels, bayonets, steel ramrods etc. but the underlying ballistic performance of the weapon remained much the same, for rifles were expensive as stated above and breechloaders even more so, not to mention often too delicate, thus the issue was far more geared towards finding effective tactics with which to employ the sturdy and cheap smoothbore muzzleloaders, which resulted in the development of the pike and shot formations in which the musketeers served a support role to the pikemen, and these configuration was what would dominate the battlefield until the 19th century, with various changes and improvements with regards to pike to shot ratio, drilling, formations, organization, firepower delivery, command and control etc. but still at heart a formation of heavy infantry supported by light infantry.
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