Alexander Grothendieck is a French mathematician, born in Germany, raised and living primarily in France, and who spent much of his working life stateless, who is the central figure behind the creation of the modern theory of algebraic geometry. His research program vastly extended the scope of the field, incorporating major elements of commutative algebra, homological algebra, sheaf theory, and category theory into its foundations. This new perspective led to revolutionary advances across many areas of pure mathematics. He consistently spelt his first name "Alexander" rather than the French "Alexandre"; his family name, "Grothendieck" is Low German, which is similar to Dutch, hence he is sometimes mistakenly believed to be of Dutch origin. After a very productive public mathematical career lasting 1949?1970, particularly 1958?1970, Grothendieck largely ceased mathematical activity after 1970, though with some private work 1970?1988. Driven by deep personal and political convictions, Grothendieck left the Institut des Hautes �tudes Scientifiques, where he had been appointed professor and accomplished his greatest work, after a dispute over military funding in 1970. 

March 28th, 1928 in Berlin  /  Died:   Nov 13th, 2014 - aged 86