Career
Born in Berlin to an aristocratic family, Oertzen followed his father into the army and trained as a general staff officer He then helped Claus von Stauffenberg to develop Operation Valkyrie. On 20 July 1944 Oertzen was the liaison officer to the commander of the defense group III (Berlin) and passed on the first Valkyrie orders.
There was no evidence of complicity in the plot until the next morning when a secretary reported having seen him with Stauffenberg.
With the arrival of the Gestapo imminent he killed himself by detonating two hand grenades.