Often referred to as “samurai swords”, katanas are perhaps the most famous bladed weapon to ever exist. As the primary weapon used by members of the Japanese warrior class, katanas are characterized by their curved blades, and exquisite craftsmanship. Although today they are mainly only used symbolically and in certain martial arts competitions, they’re still highly regarded as the weapon of a master. Here are a few things you might not know about them.
10. How the Katana Evolved
The first samurai used straight blades that were imported from China and Korea. The iconic curved blade was only developed when the samurai began fighting on horseback more often. Having a curved blade made the sword a weapon much better suited for slashing and stabbing while mounted. However, the straight bladed version of the katana continued to be widely used by another type of legendary Japanese combatant — the ninja.
http://projectyourself.com/blog/heaven-and-hell-as-told-by-an-ancient-samurai/ Via projectyourself.com