Alexander Grothendieck

After a stateless, refugee childhood, Grothendieck rebuilt algebraic geometry on new foundations — schemes, sheaves, topos and cohomology — unifying geometry and number theory and winning the Fields Medal in 1966. His father, Alexander (Sascha) Shapiro, was a Russian Jewish anarchist murdered at Auschwitz; his mother was a German writer, so his Jewish ancestry is paternal. In later life he withdrew from mathematics into seclusion in the Pyrenees.