Career
While lecturing at the University of Göttingen from 1918 to 1925, Hagen helped establish the Göttingen International Handel Festival. He came to the United States to be a professor of art history at the University of Wisconsin.
While lecturing at the University of Göttingen from 1918 to 1925, Hagen helped establish the Göttingen International Handel Festival. He came to the United States to be a professor of art history at the University of Wisconsin.