Leopold Löwenheim

Leopold Löwenheim (26 June 1878 in Krefeld to 5 May 1957 in Berlin) was a German mathematician doing work in mathematical logic. The Nazi regime forced him to retire because under the Nuremberg Laws he was considered only three quarters Aryan, and in 1943 much of his work was destroyed during a bombing raid on Berlin. He nevertheless survived the Second World War and resumed teaching mathematics afterwards. In 1915 he gave the first proof of what is now known as the Löwenheim-Skolem theorem, often considered the starting point for model theory. He was the son of Ludwig Löwenheim, a mathematics teacher at the polytechnic in Krefeld, and Elizabeth Röhn, a writer, and in 1881 the family left Krefeld for Naples and then Berlin.