The Knight's Cross (Ritterkreuz), and its variants were the highest awards in the military and paramilitary forces of Nazi Germany during World War II.

Following his graduation with the Abitur from the Gymnasium, a secondary school with a strong emphasis on academic learning, in Bergedorf, he completed his compulsory Reichsarbeitsdienst (Reich Labor Service).

[3][4] He joined the military service in the Wehrmacht with Infanterie-Regiment 66 (66th Infantry Regiment) near Magdeburg as a Fahnenjunker (Cadet) in 1936.

During this meeting, he and Oberst Karl Löwrick advocated for the introduction of the MP 43 assault rifle which Hitler initially had rejected.

[5] Von Gazen was made leader of Schützen-Regiment 66 in April 1943 and was officially commander of the regiment on 28 August 1943.

His regiment succeeded in holding the German lines in the vicinity of Melitopol against numerous attacks by the Red Army at the end of September 1943.