Ichinomiya Nagatsune was born in Kyoho 6 (1721) at Tsuruga in Province. Known initially as Kashiwaya Chuhachi, he began his career as a mekkin-shi (gilding artisan) before traveling to Kyoto, where he studied under Yasui Takanaga, a metalworker of Goto lineage. In his early period he signed "Setsuzan" (also read "Yukiyama"), later adopting the name Nagatsune and the art name Gansho-shi. He further studied painting under Ishida Yutei, who was the teacher of Maruyama Okyo -- a dual formation that profoundly informed his compositional sense and commitment to working from life. At the age of fifty he received the court title Daijo, later advancing to no Kami; he died in Tenmei 6 (1786) at sixty-six years of age.
While Nagatsune was highly skilled in Goto-style (high relief), he rose to fame above all through - (flat inlay) executed in combination with (single-bevel line carving). The consistently describes a technique in which depth and shallowness are freely commanded -- forceful, deep chisel work alternating with minute passages handled in a light, fluent touch -- something "achievable only by Nagatsune." His chisel remains keen even where it cuts over inlaid colored metals, and his designs characteristically continue seamlessly across the ridges and rim of the fitting. In works employing the Goto manner, his multi-layered achieves a sculptural richness so pronounced that carved crests appear to have been set in place, while his yobori (carving in the round) on solid gold displays superb modeling and rounded placement of form.
Nagatsune's stature is affirmed by the through recurring canonical phrases: he was acclaimed as "Somin in the East, Nagatsune in the West," and together with Tetsugendo Shoraku and Otsuki Mitsuoki he was celebrated as one of the "Three Great Masters of Kyoto metalwork." His oeuvre is praised for "assured ability," for "the earnest intensity and high technique of Nagatsune in his mature period," and for chisel work so forceful in his final years "that it is difficult to believe it dates from his very last years." His dual mastery of painting and metalwork, and his capacity to unify observational naturalism with the disciplines of kinko, secure his position as one of the most accomplished independent metalworkers of the mid- period.