An exceptionally rare Bizen period Japanese sword of wakizashi length with gold temple inscriptions. The sword is attributed to Gassan and is attributed to the 12th C.by Fred Weisberg pushing it to some of the earliest Gassan smiths. The hada is emblematic of the early Gassan school, called ayasugi hada. Ayasugi hada is basically masame hada which has been distorted by systematically varying the strength of the hammer blows along the blade during forging.
The Gassan school derives from Mt. Gassan in the province of Dewa (currently Yamagata prefecture), and is famed for a the ayasugu hada, which is now also called Gassan hada. The school was founded by a smith named Kiomaru (or Kishin Dayu, as he was also known), who lived in the sacred grounds of Mt. Gassan back in the 12th century. Since then, swordsmiths have flourished at the foot of Mt. Gassan, and a number of masters have appeared, in a long succession. From the Kamakura period through the Muromachi period, swords inscribed with the Gassan signature were famous all over the country for their practical usefulness and the beauty of their ayasugi hada, but when the Warring States period ended at the end of the 16th century, the number of blacksmiths dwindled. From the start, Mt. Gassan was a site of mountain worship, and the blacksmiths who lived there were peculiar people who secluded themselves among the mountains to purify themselves before forging swords. They were ascetics, similar to Shugendo practitioners. Gassan was the name of the object of worship, and inscribing such a name on a sword would normally be inexcusable. Probably Gassan swords were originally intended for funeral rites, rather than as weapons.
The slender proportion of this blade, the fine straight hamon indicative of early Kamakura swords and the presentation gold inscription all indicate the importance of this blade. The only flaw is small area of scratches which should be polished out and can be seen in the images below.
The importance of the blade can be double recognized by the fact that it was a temple presentation at some point in it's life with a gold inlaid inscription that translates to Kinu'omi Tada'omi, or Presentation to the Goddess Kinu and the God Tada.
Overall length is 26, cutting edge is 17 1/4.