Tachi by Norishige ca. 1300 CE, which made ō-suriage (very abbreviated) during the Edo period to be used as a "katana" by cutting and reforming the original nakago higher forefront.
Before 987, examples of Japanese swords are straight chokutō or jōkotō and others with unusual shapes. In the Heian period (8th to 11th centuries) sword-making developed through techniques brought from China through trade in the early 10th century during the Tang Dynasty and through Siberia and Hokkaido, the Ainu people territory. Ainu used warabite-To (蕨 手 刀?) And this affects nihontō, which was held with two hands and designed for cutting, not stabbing. According to legend, the Japanese sword was created by a smith named Amakuni (ca.700 AD), together with the folded steel process. The folded steel process and single edge swords had been discovered in the early 10th century Japan [12]. Swords forged between 987 and 1597 called the koto (古 刀?) (Lit., "old swords"); is regarded as the pinnacle of power the Japanese army. Initial model uneven curves with the deepest part of the curve to the handle. When the era of change tends to increase the center blade curve.
The nihonto as we know it today with a deep, graceful curve has its origin in shinogi-zukuri (single-edged sword with hills) tachi which developed around the middle of the Heian period to service the needs of the military class was growing. Shape reflects changes in the form of war in Japan. Cavalry is now the main combat units and the older straight chokutō particularly unsuitable for fighting from horseback. Curved sword is a weapon that much more efficient when wielded by a warrior on horseback where the curve is enough to add the knife downward force of the cutting action.
The tachi is a sword which is generally larger than the katana, and subject to deduction depending on the lower edge. This is a standard form of carrying the sword for centuries, and eventually will be replaced by the katana style where the blade passed through a belt worn, the top edge. The tachi is used depends on the left hip. Signature on the tang (nakago) of the blade is written in such a way that will always be outside the sword when worn. This characteristic is very important in recognizing the development, function and different styles of wearing swords this time and so on.
When worn with full armor, the tachi would be accompanied by a shorter blade in the form known as koshigatana ( "waist sword"); type of short sword with no hand-guard (tsuba) and where the handle and sheath meet to form a style of mounting called aikuchi ( "meeting mouth"). Dagger (tanto), also conducted for close combat fighting and carrying a generally for personal protection.
Mongol invasions of Japan in the thirteenth century to encourage further evolution of the Japanese sword. Often forced to abandon traditional mounted archery for hand-to-hand combat, many samurai found that their swords are too fragile and susceptible to damage when used against the thick leather armor of the invaders. In response, the Japanese began to adopt a thin and simple swordsmiths lines patience. Certain Japanese swordsmiths this period began to make knives with thicker backs and bigger points as a response to the Mongol threat. [13]
In the fifteenth century, Jidai Sengoku civil wars broke out, and needs a big sword with combat malignancy causing a very artistic techniques of the Kamakura period (known as the "Golden Age of Swordmaking") which must be abandoned and replaced by more utilitarian and disposable weapons . Nihontō exports reached its peak during the Muromachi period when at least 200,000 nihontō sent to the Ming Dynasty China in official trade in an effort to absorb the production of Japanese weapons and make it more difficult for pirates in the area of arms.
On the 15th and 16th centuries, samurai who increasingly find the need to use a sword near the residence along with the increasing use of foot-soldiers armed with spears lead to the creation uchigatana, both in one hand and the two forms. As the Sengoku civil war going on, uchigatana evolved into the modern katana, and replaced the tachi as the main weapon of samurai, especially when not wearing armor. Many more are shortened in tachi-15-17 century to meet the demand for katana.
The aircraft were destroyed as time went on and firearms were introduced as a decisive force on the battlefield. At the end of the Muromachi period, the Tokugawa shoguns issued regulations controlling who could own and carry swords, and effectively the standard description of a nihontō.
