Alexander Grothendieck — German Mathematician born on March 28, 1928, died on November 13, 2014

Alexander Grothendieck was a German-born French mathematician who became the leading figure in the creation of modern algebraic geometry. His research extended the scope of the field and added elements of commutative algebra, homological algebra, sheaf theory and category theory to its foundations, while his so-called "relative" perspective led to revolutionary advances in many areas of pure mathematics... (wikipedia)