First at all what is a sword?
I am speaking about the sword as an effective weapon used in real war combat, so forget sports, collectionists, rpg games, Hollywood and Discovery Channel.
A sword is a light, long, thin and very sharp blade with a handle. It is used to cut bodies and armors into pieces without having body to body contact.
The proble is with what material build a one or more neter long thin and very sharp blade?
The only material that can fullfil this requirement is steel.
Iron is strong, but it is not flexible and can break easily. Is impossible to make a long thin blade with iron that doesn't break at the first hit on something hard.
Bronze, even more older than iron, is more effective for a sword. Bronze is stronger and more difficult to break. Cannons were made of bronze and not of iron. You only can find small cannons made of iron, a bigger iron cannon you never can find one, it exploded at the firat shot!
The problem with bronze is that the other guys have shields and armor made of iron and you cannot break or trespasse an iron shield or armor with bronze.

The conception of the sword is simple, even a cave man could have the idea and tried to do it. Any kid makes a sword with a piece of wood. Through time many peoples and civilizations had the same idea and made it in several ways, archeologists can find many, and Discovery Channels tells you the story and Hollywood makes the movie.
The question is simple, these "swords" had any use in real war and not Hollywood?

Without steel there is not a sword, it is only an ornament or something for sports.
A simple big club is much more effective, cheap and secure than a sword that is not made of steel. No soldier would be stupid enough, even soldiers are stupid, to go to combat with a weapon that had only few minutes of use. An who used one never was able to tell you the strory, he never returned from the battle.

No steel == No sword.

Stupidity also evolves!