Otto Hahn was a German chemist who worked at the Kaiser Wilhelm Institute of Chemistry from 1912 to 1945. So you can see his tenure spanned both World Wars and he contributed to the war effort in both of these major conflicts.
But it was the work Otto did between the wars that most contributed to the war effort - but not, we must say, for his native land. The years from 1918 to 1938 were when he and his collaborator, the physicist Lise Meitner, made a most interesting discovery.
And although you may not have known about Otto and Lise, you certainly know what they discovered. And you can learn a bit more - about the discovery and about Otto, Lise, and their friends - if you just Klick hier, meine Freunde.