Max Dehn

German mathematician most famous for his work in geometry, topology and geometric group theory. Dehn's early life and career took place in Germany. However, he was forced to retire in 1935 and eventually fled Germany in 1939 and emigrated to the United States.

Dehn was a student of David Hilbert, and in his habilitation in 1900 Dehn resolved Hilbert's third problem, making him the first to resolve one of Hilbert's well-known 23 problems. Dehn's students include Ott-Heinrich Keller, Ruth Moufang, Wilhelm Magnus, and the artists Dorothea Rockburne and Ruth Asawa.

Dehn stayed in Germany until January 1939, when he fled to Copenhagen, and then to Trondheim, Norway, where he took a position at the Norwegian Institute of Technology. In October 1940 he left Norway for America by way of Siberia and Japan (the Atlantic crossing was considered too dangerous).

Dehn married Antonie Landau on 23 August 1912. He died from an embolism on 27 June 1952 at age 73 in Black Mountain, North Carolina.