Hanfried Lenz (22 April 1916 in Munich – 1 June 2013 in Berlin) was a German mathematician, who is mainly known for his work in geometry and combinatorics. Hanfried Lenz was the eldest son of Fritz Lenz an influential German geneticist, who is associated with Eugenics and hence also with the Nazi racial policies during the Third Reich. He started to study mathematics and physics at the University of Tübingen, but interrupted his studies from 1935 to 1937 to do his military service. After that he continued to study in Munich, Berlin and Leipzig. In 1939 when World War II broke out in Europe, he became a soldier in the western front and during a vacation he passed the exams for his teacher certification. He married Helene Ranke in 1943 and 1943–45 he worked on radar technology in a laborator