Okay, from my research, I know that normal swords had little chance, in the Medieval Period of Europe at least, at getting through armor like plate mail. However, weren't there much larger swords that actually could? If so... what were these swords called? How did they break through armor? Yes, I tried google and it... wasn't as helpful as usual.
Ah, thank you. Sadly, I now see my character couldn't work with something like this, but hey, thank you showing it anyway.
use something better at that job then a sword. if it must be a sword, a good stab had a better chance of penetrating armor. I know they kept refining the point of hand and a half sword so they could stab trough armor.
A war hammer or other crushing weapon could be more effective than a sword against plate armor. Really, all you needed to do was unseat the warrior from his horse. Plate armor was too heavy for most fighting on foot. It limited mobility, and restricted the warrior's range of vision. And it trapped heat. The horse was more the Achilles Heel, even with horse armor.
Good points, although I actually knew things like hammers were better. I realize now it makes no sense for my character to be using a sword anyway, but this was helpful, to say the least.
Hmmm. A Falchion comes to mind. Looks like a machete and "combined the weight and power of an axe with the versatility of a sword." - wikipedia. I've read of it being effectively used against plate armor, but how effective is "effective", I don't know. Good luck either way.
If I remeber correctly certain two handed swords (don't ask me the names, I've not got my books handy) were more designed to crush than cut, anything with a heavy blade should work as the principle behind weapons designed to fight plate armour is more to crush and inflict blunt trauma to the target. From waht I've read it was more common for people to be crushed by the blow than sliced and diced.
Oh, here's a good resource for sword related research http://www.thearma.org/SwordForms.html. I hope it helps you find the correct weapon for your character to use, if not perhaps arm him with a suitable dagger (the rondel comes to mind as it is designed to go through the gaps in the armour).
You could try something more oddball. I sharpen knives made from hammered and folded Japanese steel. When they made swords, they did what was known as a "differential heat treatment." Using a clay slurry, they coated the upper and lower halves of the blade "differently" for the quench. Not only was the blade now differentially hardened, but it had a decorative pattern called a "hamon line." The spine of the blade was 'tougher' to withstand blows, and the edge was now "glass hard" for superior slicing.
As far as I know about "Battle with sword" Usually they cut the joint of armor. Like if plate mail, cut the joined ring or stab where's no protection (I'm pretty sure every plate mail consider with flexibility too. That means, some human anatomy that need most move are not mailed). One handed sword are not strong enough. But two handed sword is better and long one (usually called long sword). There some technique of two handed sword to strike not cut. (I don't know if it's true) If I were you, I would focus to the vital area than facing the plate mail head on. If you are going research with this two handed sword start from german -> Zweihander -> Codex wallerstein But, i'm thinking about a poisoned dagger that stab the gap of plate armor Or you really want a sword that cut through armor, there's a legend about damascus steel beyond the holy war. It's pretty popular, doesn't know it is true or not