Theodor Ilgen
Theodor Ilgen was a German archivist and historian.
He studied history at the University of Marburg as a pupil of Conrad Varrentrapp. In 1879 he received his doctorate, and afterwards worked as an archivist at the state archives in Marburg, Düsseldorf and Münster. From 1900 to 1921 he was director of the archives at Düsseldorf.
He published German translations of Aeneas Silvius' book on Holy Roman Emperor Friedrich III and Josef Grünpeck's work on Friedrich III and Maximilian I. He made contributions as editor to and was the author of several biographies in the Allgemeine Deutsche Biographie.