[3] Early on in World War I, Karl served in the German Army with Field Artillery Regiment 17 in August 1914.

[1] After World War I, Eberstein fought as a member of the Freikorps in Middle Germany and/or Upper Silesia,[1] and also with the Halle "Protection Police".

[5] According to Jonathan Petropoulos, Eberstein was part of Himmler's strategy to attract members of the nobility and aristocracy to the SS.

His rise in that organization was rapid, being promoted to SA-Standartenführer in February 1931, SA-Brigadeführer in November 1931 and, finally, SA-Gruppenführer on 15 September 1932.

[9] Eberstein played a part in the first meeting of the two major leaders of both the SS and later the Holocaust: Reinhard Heydrich and Heinrich Himmler.

At 2:10 Eberstein sent a telegram to the State Police HQ of Augsburg, Nürnberg, Würzburg, and Neustadt a.d. Weinstraße, the Regierungspräsident, and the Gauleiter, with the subject line "Anti-Jewish Measures".

It concluded: "...Every effort will be made to arrest immediately as many Jews as the jails will hold, primarily healthy male and well-to-do adults of not too advanced age".

Evans, in defense of Lipstadt, claimed that it made no sense for Eberstein to send his telegram of 2:10 a.m. if he had earlier that night listened to Hitler tirade angrily against the pogrom.

Meinel discovered the murders were going on, and refused to follow orders to send several hundred of the remaining "screened out" Soviets to Dachau.

These telegrams state that von Eberstein telephoned the Reich Security Main Office or Reichssicherheitshauptamt (RSHA)[18] and told them that it was "intolerable" for Meinel to stay in his position, and it would cause problems with the relationship between the military and the SS.

[17] On 12 March 1938, Eberstein was appointed Higher SS and Police Leader (HSSPF) for military district VII in Munich.

Karl von Eberstein was dismissed from all posts on 20 April 1945 for "defeatism", by Gauleiter Paul Giesler, on orders from Martin Bormann.

[8][20][21] In his testimony, Eberstein gave organizational and historical information about the SS, the SA, their relationship with the German nobility, the Nazi Party, the SD (Security Service) and the Gestapo (Secret State Police).

He also briefly discussed the treatment of downed enemy pilots, per the Geneva Convention and Hague Rules on Land Warfare.

Eberstein stated there was no reason to inspect the camps, and he had no right to do so; they appeared to be run sufficiently and during the war inmates looked "well fed".

In the fall of 1944 Himmler transferred to the Higher SS and Police Leaders the responsibility for safeguarding prisoner-of-war camps against mass escapes and against attempts from the outside to liberate prisoners.

For this purpose, the Higher SS and Police Leaders were made senior commanders of the prisoners of war in their defense areas.

He stated the general SS mostly ceased to exist by the start of the war, and that the Gauleiters and "Reich Defense Commissioners" under Martin Bormann were to blame.

Eberstein stated he was in Munich during the entire war, thought foreign newspaper reports of atrocities were "enemy propaganda", and said it was impossible to "penetrate into the secret sphere of these extermination camps".

On 15 November 1948, Eberstein was classified by a German Denazification court as a (class III) Nazi and ordered to forfeit 30% of his wealth.