http://en.wikipedia.org/wiki/Karl_Schwarzschild
Read a fair bit on the guy over the last year or so .. I read Albert wrote to thank him on the publication of his paper regarding his solutions to the field equations einstein published the previous year ..
While Karl could never know the significance of his publication
..Dieing shortly after , aside whether you believe a black hole exists or not , the mathamatical solution to show they VERY much can ..hasn't really been disputed for over 90 years .