It was during the Heian period (794-1185) that an important feature of samurai swords was developed. The era began after Emperor Kammu, the 50th Emperor of Japan, moved the country’s capital from Nara to Heian-kyo (present day Kyoto).
Four clans dominated the politics of the Heian period: the Minamoto, the Taira, the Fujiwara, and the Tachibana. At the end of the era, conflict between the Minamoto and the Taira clans erupted, which led to the Genpei War (1180-1185).
Throughout this time, Confucianism, Buddhism, and other Chinese influences were at their pinnacle. The Heian period is regarded as the peak of the Japanese imperial court. It is also noted for its art, particularly literature and poetry, as well as the rise of the samurai warrior class. Heian means “peace and tranquility”.
The Legend of Amakuni
The sword making technique of wrapping a tougher outer skin steel around a softer inner core steel was devised during the Heian period. The oldest handmade swords forged using this method can be traced back to the Ko-Bizen tradition, around 950 A.D.
According to legend, a swordsmith named Amakuni developed this technique and made the first single-edged curved tachi (long sword). He is also believed to have created the Kogarasu Maru (Little Crow), a unique double-edged sword that is now in the Imperial Household Collection.
Legend tells that Amakuni was the head of a group of swordsmiths who worked for the Emperor of Japan. One day, he and his son Amakura were standing in their shop’s doorway, watching the Emperor’s army return from battle. As the Emperor himself passed by, he ignored Amakuni instead of giving him the usual praises for his good work on the blades. Amakuni then saw that several of the japanese samurai were carrying broken swords, which were chokuto (straight swords).
Disappointed yet determined to make amends, Amakuni and his son gathered what remained of the swords and scrutinized them. It seemed that the swords had broken due to improper forging and hitting hard objects, most likely samurai armor and other samurai weapons.
Amakuni did not eat or drink for a week and spent his time finding a better way to make swords. Legend has it that Inari, the kami (spirit or god) of swordsmiths, appeared to him in a dream and taught him how to wrap a harder skin steel around a softer core steel, and how a curved blade is more effective than a straight one.
After thirty one days of working without rest, Amakuni and his son emerged from their forge with a single-edged curved katana sword. They continued improving on the new design for the subsequent months. Another war came the next spring, and when the army returned, Amakuni saw that all of the samurai’s swords were intact. When the Emperor passed by, he was told that he was an “expert swordmaker”.
Tachi
Tachi were widespread during the Heian period. During this era, it became the norm for swordsmiths to put their mei (signature) on the blades they forged. Possibly the oldest signed sword is a tachi made by Sanjo Munechika, while the oldest tachi with both a mei and date on it is an 1159 tachi by Naminohira Yukimasa.
Tachi samurai swords of the Heian period was characterized by a wider mihaba (width) near the nakago (tang) than that near the kissaki (point); a ko-kissaki (small point); not much sori (curvature) near the monouchi (first six inches from kissaki) but present on the rest of the blade; a suguha (straight temper line); a relatively short nakago; and a hawatari (length) of approximately 75-80 cm, making it suitable for striking enemies on the ground while on horseback.
