I have read that Spears were by far the most dominant weapon used in battle prior to the invention of gunpowder. However, I would like to know is how often were maybe more unconventional weapons such as axes, maces, and flails? What were the advantages of such weapons? Were there specific time periods when they were used more than others?
Flails like you see in cartoons were actually never used, they were made up in the 1700s as display pieces and are horribly impractical in battle. A different kind of flail, with a long handle and short chain, was sometimes used, but it wasn’t very common. It was an improvised weapon made from a farm tool of the same name.
One-handed axes and maces were common side-arms for poorer soldiers who couldn’t afford swords(which were also side-arms), but maces were also commonly used on horseback by mounted knights.
Two-handed axes were pretty common primary weapons in the Early and even High Middle Ages, especially in places like England and Scandinavia, as can be seen on the Bayeux Tapestry. Two-handed axes are often called “Dane axes” because of their association with the Danes in this time period.
In the Late Middle Ages, you didn’t really need to choose between a spear and an axe for your primary weapon because they were often combining the two. Some examples of this include the “halberd” and the “poleaxe”, as well as many other examples of polearms that have a thrusting tip and also a dedicated cutting edge.
The advantages and disadvantages of an axe vs a sword are too nuanced and complicated for me to get into in a reddit post. I’d be here typing for hours.
But maces had a pretty distinct anti-armor role in combat(not that they won’t bang up an unarmored person just as well).
Despite what you see in movies, swords, spears, axes, etc. actually don’t penetrate armor very well. Medieval soldiers wouldn’t have worn any armor if it didn’t work. Swords can’t cut through maille armor and even often have a hard time getting through padded cloth armor(not because medieval swords were dull, they just made really good padded cloth armor back then), and axes can sometimes bust through it but not very cleanly or deeply; and only the most perfect and powerful of sword and spear thrusts can ever hope to penetrate maille. Plate armor, as seen in the Late Medieval Period and Renaissance was virtually impenetrable to ANY weapon. Late Medieval plate armor could even block bullets from early guns. In fact, that’s where we get the term “bulletproof” from. Late Medieval and Renaissance armorsmiths would shoot their armor with a gun as a form of advertisement. The dent made by the gun was call a “bullet proof”, as in proof that the armor could not be penetrated by bullets.
However, concussive force can still carry through armor like that, and maces are very good at concussive force and nothing else. If you hit a plate-armored man in the head with a sword, he might not even feel it unless you put your entire bodyweight into it(which is generally a bad idea in any martial art, because it takes a lot of energy and can throw you off balance), but if you hit him with a mace, that carries a lot more force because it’s heavier on the striking end, and it could result in a concussion even with the best of helmets.
Also, i should clarify, that maces were actually largely replaced by warhammers, which served the same purpose, in the Late Middle Ages.