When most people think of the medieval times, a few things come to mind; castles, princesses, kings, and of course, knights in shining armor. Sadly, there are a lot of misconceptions about medieval knight armor. Many people believe that knight armor was the end all be all of the battlefield and it simply dominated. This isn't necessarily untrue, but it's not true either. The fact of the matter is, knight armor came around late in the medieval period and didn't actually get to see as much use as it probably would have liked, as it was rendered obsolete by the widespread use of gunpowder weapons starting in the late 15th century.
As most people know, medieval knight armor started out with chain-mail. Chain- mail was created by interlocking tens of thousands of small metal rings. To prevent these rings from pulling apart in combat, each one had to be individually riveted together. As I'm sure one can imagine, this is a painstakingly long process. Chainmail was proven over time to be more and more ineffective with the invention and use of weapons like the longbow and crossbow. Eventually, in the late 13th and early 14th century, plate-mail began to appear. Not as a full suit, but originally just to reinforce certain vital areas. The fully armored knight appeared in the early 15th century.
While knight armor didn't get to see a lot of use on the battlefield, in the time in which it did, knights were crucial. Medieval knight armor was amazing protection against the full complement of deadly medieval weapons. Swords, bows, crossbows, maces, battle axes, all rendered nearly useless against a fully armored knight. Knight armor was designed to protect them from nearly anything new that was developed. Unfortunately, they could not have foreseen the development of guns. Once gunpowder was widely used on the battlefield, knight armor was mostly regulated to ceremonial duty. It became much more ornate, with extensive carvings and detail.
Knight armor consisted of a complex series of plates and other garments held together by leather straps and buckles. It was time-consuming and heavy to put on, weighing about 50 lbs in all, but was however, light enough so as to provide maximum mobility in combat. It had to be tailor made to fit each knight individually, as even the slightest imperfection could hamper their ability to fight.
Each piece of armor had a unique name and protected a certain area of the body. Those pieces of armor were as follows:
Head = Helmet
Neck = Gorget
Chest = Cuirass
Shoulder = Pauldron
Arm = Vambraces
Hands = Gauntlets
Thighs = Cuisse
Elbows = Couter
Knee = Poleyn
Calves = Greaves
Feet = Sabatons
Eventually, knights faded into history and myth, their armor along with them. Of course, you can still find a perfectly good suit of plate-mail in a museum, or even perhaps in your house, if you're rich enough. But no one is going to put it on and walk into battle. No, those days are over.