Answer
The highest military rank obtained by Sepp Dietrich, a prominent figure in Nazi Germany and a member of the Nazi Party, was that of Oberst-Gruppenführer. This rank was equivalent to a Generaloberst or Colonel-General in the German army and was the second-highest rank in the Waffen-SS, the armed wing of the Nazi Party. Dietrich held this rank from 1944 until the end of World War II.