History of Swords
When you think about weapons today, swords are probably not the first thing which come to mind. But, the fact of the matter is that swords used to be the most feared weapons on the battlefield. Dating back as far as the 16th centry, swords have come a long way. They were most likely developed during the Bronze Age by someone who said, "What if we made this dagger really, really big?" But, if you know anything about metals, you know bronze isn't very strong and made it difficult for swordsmiths to make long blades that wouldn't bend in battle. So, swords during the Bronze Age were actually more like a large leaf shaped bowie knife. It wasn't until better materials and improved heat treating came around that swords became closer to what we know them as today.
Bronze swords from ca. 1600 BC
Following the Bronze Age, swords were iron swords. These were a little stronger than bronze, but they were easier to produce and the raw material was readily available, so iron swords became more common and you began to see entire armies with metal weapons. This trend continued and blacksmith technologies advanced. During the Middle Ages, swords were used during battle quite frequently. And though sword making advancements continued, so did the advancement of armor techniques. This made it more challenging to wound an opponent during battle with a sword swung with only one hand. Thus, the hand and a half sword was brought about during the 14th century. This larger sword that could be wielded with two hands allowed swordmen to cut even through strong army with such a powerful blow.
Medieval Long Sword
Many swords today are produced overseas with stainless steels versus carbon. The stainless allows these blades to be sharpened to the same razor's edge as carbon steel, but the low carbon content allows these blades to resist corrosion. Many swords today are purchased as home decor and the ability to be functional is irrelevant for those. That is not to say there aren't great functional swords stil being produced today. One great functional Japanese Katana brand is Shinwa. All of their swords are crafted by only veteran bladesmiths and each blade is hand-forged of carbon steel. While this isn't an entire history on swords in every continent, it should allow you a better appreciation for the hobby of sword collecting.