I shall concentrate upon the two subjects that were Drinfeld´s main preoccupation in the last decade. These are Langland´s program and quantum groups. In both domains, Drinfeld´s work constituted a decisive breakthrough and prompted a wealth of research. (Y.I. Manin, ICM Proc. 1990, p.3)

His work on knot polynomials, with the discovery of what is now called the Jones polynomial, was from an unexpected direction with origins in the theory of von Neumann algebras, an area of analysis already much developed by Alain Connes. It led to the solution of a number of classical problems of knot theory, and to increased interest in low-dimensional topology. (https://en.wikipedia.org/wiki/Vaughan_Jones, 2018)

The most profound and exciting development in algebraic geometry during the last decade or so was the Minimal Model Program of Mori´s Program in connection with the classification problems of algebraic varieties of dimensions three. (Hironaka, ICM Proc. 1990, p.19)

Althought he is definitely a physicist his command of mathematics is rivalled by few mathematicians, and his ability to interpret physical ideas in mathematical form is quite unique. Time and again he has surprised the mathematical community by a brilliant application of physical insight leading to new and deep mathematical theorems. (Faddeev, ICM Proc. 1990, p.27)

Photos: ICM 1990 Nippon Hyoronsha Co.,Ltd. Publishers (Photographer : Hiroaki Kawano)