Heisuke Hironaka (広中平祐) (born 1931) is celebrated for proving in 1964 that singularities of algebraic varieties admit resolutions in characteristic zero. This means that any projective variety can be replaced by a similar one (i.e. birationally equivalent) which has no singularities. For this theorem he won the Fields Medal in 1970. He was for many years a professor of mathematics at Harvard but currently lives in Japan where he is greatly respected and influential. He has been active in raising funds for causes such as mathematical education.
