Sugata (Configuration): Shinogi-zukuri, Iori-mune. The blade is a bit on broad side in width with a substantial kasane, exhibiting a deep koshizori curvature and even a slight curvature extending into the tang. Toward the upper section around the Monouchi, the blade displays a gentle tapering inclination, presenting the classical appearance of a Tachi. (See enlarged blade photograph)
Jigane (Forging Pattern): A finely forged Ko-mokume hada, densely compacted and covered with sparkling Ji-nie, accompanied by exquisitely refined Chikei.
Hamon (Temper Pattern): The Yakidashi begins with a long, straight section at the base. The Hamon is predominantly Nioi-based and forms a brilliant Jūka-chōji midare, incorporating reverse-leaning Chōji, chrysanthemum-shaped Chōji, and fist-shaped Chōji. The pattern varies in width, creating a lively and magnificent appearance. The interior of the Hamon is filled with clear, luminous Nioi, appearing pale blue-white and transparent. Chōji-ashi enter the blade edge at varying angles toward the Ha-saki, while the Habuchi remains sharply defined and remarkably bright.
Nakago (Tang): Ubu. Two Mekugi-ana, one of which has been plugged. Katte-sagari Yasurime. The Nakago-jiri is Kurijiri with Ha-agari. On the Omote Shinogi-ji is an expertly executed long signature carved with distinct chisel strokes:"Yokoyama Kaga-no-suke Fujiwara Sukenaga" 横山加賀介藤原祐永.
The reverse bears a sixteen-petal chrysanthemum crest and the character "Ichi" (一), together with "Bizen Osafune Jū" 備前長船住 and the date "A Day in the Second Month of Tenpō 14 (1843)" 天保十四年二月日
Bōshi (Tip Temper): The Hamon forms a large Gunome at the Yokote, followed by a single Gunome, then turns into a rounded medium Bōshi and turns deeply.
Yokoyama SUKENAGA 横山祐永 was the second son of Yokoyama SUKEHIRA 祐平 and his personal name was Yokoyama Kakunosuke 横山覚之助. Since his elder brother SUKEMORI 祐盛 became the adopted heir of Go-Shichibee Sukesada 後七兵衛祐定, SUKENAGA 祐永 succeeded to his father's house on the 1st day of the 12th month of Bunsei 12 (1829) and entered service as a swordsmith of the Bizen domain.
On the 13th day of the 2nd month of Tenpō 4 (1833), he was granted the honorary title Kaga-no-Suke 加賀介. At that time, the Imperial Court authorized him to carve the sixteen-petal chrysanthemum crest and the character Ichi 一 upon his works. Some of his signatures further proclaim him as "the fifty-sixth-generation descendant of Tomonari" 友成五十六代孫 asserting his position as the legitimate heir to the Bizen Ichimonji tradition. He died on the 2nd day of the 6th month of Kaei 4 (1851) at the age of 57.
The present sword was forged in Tenpō 14 (1843) when SUKENAGA 祐永 was 45 years old. The inscription was engraved by his fellow-school smith SUKENORI 祐則 (see note below). The blade exhibits a deeply curved Tachi-style form with pronounced Koshi-zori. Its Jihada is exceptionally beautiful, consisting of a tightly forged and highly refined Ko-mokume texture. The hamon is an elegant Nioi-based Chōji-midare, flourishing across the blade like a profusion of blooming flowers.
Modelled after the Tachi of the great old Ichimonji masters, this work represents the legitimate continuation of the Bizen tradition. It stands as a masterpiece from the prime years of SUKENAGA 祐永 who served as a swordsmith to the powerful Bizen domain of 300,000 koku.
Fitted with a single-layer silver Habaki and preserved in a Shirasaya.
Note: Some swords by SUKENORI 祐則 also bear the inscription "the fifty-sixth-generation descendant of Tomonari," just as on works by Sukenaga. The three Yokoyama smiths who served the Bizen domain—Sukehira, Sukenaga, and Sukekane—were collectively celebrated as the “Three Crows of Osafune” (Osafune Sanbagarasu) in recognition of their exceptional skill and achievements.
