Wilhelm Wirtinger (1865-1945). Born in Ybbs, Austria. Studied mathematics at the University of Vienna. Received his doctorate in 1887, and continued his studies at the Universities of Berlin and of Göttingen. From 1895 a full professor at the University of Vienna, but accepted professorship at University of Innsbruck, returning to Vienna only in 1905. Wrote an important paper on the general theta function and had an exceptional range in mathematics (function theory, algebra, number theory, plane geometry, theory of invariants).