Successful wartime military service earned him a knighthood in 1916. After the end of World War I and the dissolution of the German Empire, von Epp was a commanding officer in the Freikorps and the Reichswehr. He was a member of Bavarian People's Party, before joining the Nazi Party in 1928, when he was elected as a member of the German parliament or Reichstag, a position he held until the fall of Nazi Germany.