Shōkichi Iyanaga

Shōkichi Iyanaga (1906–2006) was a Japanese mathematician who carried the torch of Teiji Takagi's class field theory into the twentieth century, becoming one of the principal architects of the modern Japanese mathematical school. A student of Takagi at Tokyo Imperial University from 1926, Iyanaga later studied in Europe with Artin and Hasse, becoming a bridge between the Japanese tradition of structural arithmetic and the European schools that had initially inspired it. His textbook The Theory of Numbers became a standard reference, and his leadership of the Japanese Mathematical Society helped transform Japan into a major center of mathematical research after the Second World War.

Iyanaga lived a century and witnessed the full arc of Japanese mathematics: from Takagi's solitary creation through international integration to world leadership. His role was not merely preservation but transmission — ensuring that Takagi's insights survived the war and found new generations of students who could extend them.