Kantei
A long, curved tachi on a black background, with its signed tang on the left and its reflection below.

Swordsmith of Osaka (1869–1943) · Gassan school

Gassan Sadakatsu (月山貞勝)

The third head of the Gassan house of Osaka, who forged for the imperial household and the Ise shrine and was the master of his son and of Takahashi Sadatsugu, both later Living National Treasures: his life, his work and his sources

The eldest son of Gassan Sadakazu, he inherited the Gassan house of Osaka in 1918. He forged for the imperial household, for the Ise shrine and for the Army, mastered the ayasugi-hada of his school and trained his son, the second Sadakazu, and Takahashi Sadatsugu, both later Living National Treasures. He himself never became one: he died in 1943, before that title and the NBTHK competitions existed.

Photo: dealer outside Japan

1869
Born in Osaka
1918
Signs with his own name
1927
Ise commission
1943
Dies
On this page
  1. Quick profile
  2. In short

Quick profile

Name
Gassan Sadakatsu PC
Kanji and reading
月山貞勝 (Gassan Sadakatsu) HD
Birth
1869 (Meiji 2), in Osaka AT
Death
1943, aged 74; on 24 December according to almost all sources, on 24 February according to the Kitano Tenmangū shrine PC
Where he forged
Osaka; from 1935, also on Mount Yoshino (Nara) AT
Master
His father, Gassan Sadakazu (月山貞一, Gassan Sadakazu), artist of the imperial household AT
School or tradition
Gassan (月山, Gassan), Osaka branch; third head after Sadayoshi and Sadakazu AT
Rank
Saijō-saku (最上作, saijō-saku), the highest grade in Kurihara Akihide’s ranking, with eleven other swordsmiths AT

In short

He learned from childhood under his father, Gassan Sadakazu, and until the latter’s death, in 1918, worked under his name; from then on he signed as Sadakatsu and ran the Osaka house. From 1921 he received commissions for the emperor, the imperial household and senior military officers; in 1927, with his son, the commission for the ritual swords of the Ise shrine, and in 1929 they forged together a sword for the Emperor Shōwa. During the war he was an Army-designated swordsmith.

His pupil Takahashi Sadatsugu was a Living National Treasure from 1955, and his son, Gassan Sadakazu II, from 1971.

Sections

  1. Osaka · the imperial household · Ise Life and forging His apprenticeship with his father, the imperial and Ise commissions, the war and his pupils.
  2. Ayasugi-hada · Bizen · Sōshū Work and style The ayasugi-hada of the Gassan, his carvings and his best-known works.
  3. Before the NBTHK Prizes The honours of his time and why he has no NBTHK prizes.
  4. Bibliography and credits Sources The sources consulted on 4 October 2026, with their link where possible, and the credit for the image.