Kôzuke no Daijô Sukesada (上野大掾祐定) was the son of Shichibei no Jô Sukesada (七兵衛尉祐定) and was active around the Jôo (1652-1655), Meireki (1655-1658), Manji (1658-1661), and Kanbun (1661-1673) eras. He was born in the tenth year of Kan-ei (1633), his first name was Heibei (平兵衛) and he died in the sixth year of Kyôhô (1721) at the age of 89. He is regarded as the best and most representative Bizen Osafune smith of the Shintô period. From the time he received the title of Kôzuke no Daijô in 1664, he signed his works using that title in his signature. Before that time, however, details about his life are somewhat limited. This might be because when he was born in 1633, his father was already 57 years old. When he began his sword making under his father’s tutelage, he spent much of his time making daisaku blades for his father. A Daisaku blade is a blade that is made by the student under the master’s guidance that is signed by the master. It is regarded as being shôshin (genuine).
In the second year of Enpô (1674), Kôzuke Daijô Sukesada’s (上野大掾祐定) father, Shichibei no Jô Sukesada (七兵衛尉祐定) passed away at the age of 98. At that time, Kôzuke Daijô was 41 years of age. From around the Jôkyô era (1684-1688), we see daimei blades made together with his younger brother, Shishinoshin Sukenobu (七之進祐信) whom Kôzuke Daijô Sukesada’s (横山上野大掾祐定) later adopted and made his successor.
Sukenobu changed his name to Sukesada and late in his career (the sixth year of Shôtoku, 1716), he became Yamato Daijô Sukesada (大和上野祐定). Yamato Daijô Sukesada (大和上野祐定) supported Kôzuke Daijô Sukesada throughout the last thirty years of Kôzuke Daijô’s career. Since the receipt of the Yamato Daijô title and his subsequent succession took place late in his career, signed works in his own name are quite rare. There is no doubt, however, that judging from gassaku blades that exist his work was very close in skill level to that of his father, Kôzuke Daijô. A Gassaku blade is a joint effort by two or more smiths (often a student and master) and signed by both smiths.
I am very pleased to offer this fine katana by Bizen Kôzuke no Daijô Sukesada (備前横山上野大掾祐定). The full signature reads, Bizen (no) Kuni Osafune Kôzuke Daijô Fujiwara Sukesada Saku (備前國住上野大掾藤原祐定作). It is dated as having been made on a day in February of the in the sixteenth year of Genroku (1703).
This is an unusually large blade for this time in Japanese history when sword length was supposedly regulated. It has a nagasa (cutting edge) of 29 9/16 inches or 75.1 cm. The moto-haba is 1.25 inches or 3.2 cm. The saki-haba is 0.78 inches or 2.0 cm and the kasane is thick, measuring 0.34 inches or 0.87 cm. It has a somewhat strong koshi-zori measuring 0.86 inches or 2.17 cm. Also please note that the nakago shows little rust for the age of this sword. This shows that this sword was treasured and well cared for by its former owners over the last 300+ years.
Unlike the prevailing Kanbun-shintô sugata of his time with their shallow sori, Sukesada’s blades show a tendency towards koshi-zori and feature some funbari. These are unique traits that go back to his roots in the Bizen tradition. This blade certainly shows those traits.
The hada is a densely forged ko-itame that is partially mixed with mokume. This beautiful katana also shows a characteristic feature of Kôzuke Daijô Sukesada in that there is a clear mizukage near the machi.
As with all of his blades, this blade’s midareba starts with a sugu-yakidashi. The yakidashi shows similarities to an Ôsaka style yakidashi, because it widens as it connects with the hamon. The hamon shows the very distinctive traits of Kôzuke Daijô Sukesada in that it is formed of a unique gunome where the gunome elements are arranged in groups of four with a distinct wide tani (valley) separating the groups of four. Closer inspection, however, reveals that the “groups of four” are really comprised of two groups of double gunome (fukushiki-gunome) that are separated by a smaller and shallower tani(valley).
The yakigashira (or heads of the gunome) of Kôzuke Daijô Sukesada’s earlier works will be roundish while his later works will often be more of a togari-ba shape (peaked). Sometimes a blade will start out with one form and then transition into the other. An alternative name for this type of fukushiki-gunome with peaked yakigashira will be kani-no-tsume (crab claws). This blade exhibits these forging traits perfectly.
The bôshi is a somewhat peaked ko-maru shape with the characteristic short kaeri (return). The shows his typical somewhat bulbous kurijiri and the yasurimei are katte-sagari.
Kôzuke Daijô Sukesada had a very distinctive signature using several variations of parts of certain key kanji. Judging from the fact that this blade was made when Sukesada was 70 years and from the way this blade is signed, I think that there is an excellent chance that this is a daimei sword that was made by Kôzuke Daijô Sukesada and signed by Yamato Daijô Sukesada (大和上野祐定). This blade has been awarded NBTHK Tokubetsu Hozon papers and a NTHK Kanteisho guaranteeing the the authenticity of this blade.
The blade is accompanied by a very attractive set of koshirae that is pictured above. The saya is a 20th century copy of a famous saya owned by Toyotomi Hideyoshi and the remainder of the kodogu comprising the koshirae are from the Edo Period (1600-1867).
For more information about this smith, please refer to the following article, Kôzuke Daijô Sukesada.