After secondary school Friedrichs enlisted in the German Imperial Army in 1916, seeing service in the First World War.
Serving with the Freikorps and the army, he joined with Karl Dincklage, later a Sturmabteilung (SA) leader, in campaigning for the German National People's Party.
[2] In this role he served as liaison between Hess and Martin Bormann, meeting the former weekly to obtain his general policy ideas before passing these on to Bormann who then developed specific initiative based upon Hess's initial ideas.
[8] Along with Gottlob Berger he was also appointed as one of the two Chiefs of Staff of the Volkssturm upon the foundation of this civil defence force in 1944.
[9] Friedrichs was reported missing from February 1945; on 13 August 1951 he was declared legally dead by the Munich district court with his date of death officially set as 31 December 1945.