Swords used by samurai have evolved throughout the different periods of Japanese history, and the Edo period (1603-1868) brought in the shinto (new swords) and shinshinto (new revival swords, or literally “new new swords”). Shinto were made with new materials and new techniques, while shinshinto were made in the style of koto (old swords).
The Edo era was governed by the Edo or Tokugawa shogunate, established by Tokugawa Ieyasu, the first Edo shogun. It is known as the start of Japan’s early modern period.
The Edo period can be divided into five sword periods.
Keigen-shinto period (1596-1623)
During the Keigen-shinto period, several tachi (long swords) made in the Nambokucho era were shortened to 70 cm so that they may be worn at the waist, which was brought about by the new combat style and fashion. Mihaba (width) near the kissaki (point) and nakago (tang) were similar, while the point was large (o-kissaki); this blade shape gained popularity. The main difference between Nambokucho and Keigen-shinto japanese swords was the kasane (blade thickness), which was thick on Keigen-shinto blades.
In this period, the influence of European culture grew, and many products were imported from Europe, including iron. This European iron was termed nanban-tetsu, meaning “steel of the Southern Barbarians”. However, it was not suitable for making nihonto due to the impurities it contained; thus, swordsmiths stopped using it later on.
Kanbun-shinto period (1658-1683)
The Kanbun-shinto period saw Edo and Osaka become the centers of hand made sword making. These two cities produced different styles of swords that were reflective of their different personalities.
As Edo was the heart of military power (the shogunate), swordsmiths gave importance to the sharpness and efficiency of the blade. The hamon (temper pattern) was wide, and the main cutting part of the blade (monouchi) was softened for better shock resistance. Kotetsu is the most famous swordsmith of the Edo school of this period.
Osaka, on the other hand, was the country’s business center. Traders were lower than samurai in the caste system and forbidden to own long swords, so more wakizashi were produced in Osaka. Most swords featured yakidashi (hamon that began just above the ha-machi), and toran (high wave-like hamon) became popular. The most well-known smith of the Osaka school of this period is Sukehiro.
Genroku-shinto period (1684-1763)
Genroku is regarded as a golden period for manufacturing and art. People acquired lavish habits and became corrupt, samurai included. Despite Shogun Tokugawa Yoshimune’s efforts to improve the situation, this period was a struggle for swordsmiths due to the samurai’s dwindling martial spirit. Good finances became more important than good fighting capabilities, so the demand for high quality swords declined.
Swords of this period were not as straight as those from the Kanbun-shinto era. Instead, they were curved, and the width near the kissaki was narrower than that near the nakago. In order to sell more swords, swordsmiths began to add designs to the hamon. Some common ones were Mount Fuji, mums on water, and those with fantasy themes.
First half of shinshinto (1764-1829)
The swords of this era imitated the Osaka school of the Kanbun-shinto period. Suishinshi Masahide, a famous swordsmith of this time, advocated the revival of the koto methods. Thus, swordsmiths began to make their own steel in an attempt to replicate the superior quality of koto blades.
Second half of shinshinto (1830-1868)
Swords of this period had a stronger shape; they were wider and longer, and looked like the tachi used by samurais in the Nambokucho era. Swordsmiths continued to try to reproduce koto swords, but beginning in 1868, as the Tokugawa shogunate fell, so did the quality of swords.