Matthias Grünewald or "Mathis" (as first name), "Gothart" or "Neithardt" (as surname) (c. 1470 – August 31, 1528), was a German Renaissance painter of religious works, who ignored Renaissance classicism to continue the expressive and intense style of late medieval Central European art into the 16th century.
Only ten paintings—several consisting of many panels—and thirty-five drawings survive, all religious, although many others were lost at sea in the Baltic on their way to Sweden as war booty. His reputation was obscured until the late nineteenth century, and many of his paintings were attributed to Albrecht Dürer, who is now seen as his stylistic antithesis. His largest and most famous work is the Isenheim Altarpiece created between 1506 and 1515.
Source: Wikipedia, "Matthias Grünewald", available under the CC-BY-SA License.