Short answers, pulled from the story.
The first weapons that can be described as swords date to around 3300 BC, emerging from the arsenical bronze workshops of Arslantepe in Turkey. These early blades were about 60 centimeters long and featured silver inlays, suggesting that even in the dawn of the Bronze Age, the sword was a symbol of status as much as a weapon of war.
Iron became increasingly common from the 13th century BC, fundamentally changing the landscape of warfare and the design of the sword. The easier production and better availability of raw materials meant that entire armies could be equipped with metal weapons, a feat that was impossible with bronze.
The types of swords used by the Samurai included the odachi, tachi, katana, and wakizashi, each serving a specific purpose in the complex social and military hierarchy of feudal Japan. The katana, with its curved, single-edged blade, was designed for slashing and cutting, while the tachi was a long cavalry sword.
The rapier is believed to have evolved either from the Spanish espada ropera or from the swords of the Italian nobility somewhere in the later part of the 16th century. The rapier differed from most earlier swords in that it was not a military weapon but a primarily civilian sword used for dueling.
It was not until the late 1920s and early 1930s that this historic weapon was finally discarded for all but ceremonial purposes by most remaining horse mounted regiments of Europe and the Americas. Swords and other dedicated melee weapons were used occasionally by many countries during World War II, but typically as a secondary weapon as they were outclassed by coexisting firearms.