While Wilhelm Canaris was Chief of The Abwehr Military Intelligence, the young Reinhard Heydrich was Chief of Security SD.
The relationship between Canaris and Heydrich originated in the 20ís when Heydrich was a cadet and received his training on a schoolship called Berlin and the First Officer of the ship at the time was Canaris. What made Canaris first notice Heydrich was that he played the violin. His wife, Erika Canaris, herself an accomplished violinist, invited young Heydrich to their home and was surprised at his musical talent. He soon became a regular guest at her Sunday musical parties, taking part in Haydn and Mozart string quartets.
Heydrich was aware of Canarisí importance, they got closer and held small houseconcerts and cooking dinner together during the years. But though they had close personal ties there certainly were frictions over turf from very early on. Heydrich's career was rapid, and at his death in 1942 he was Obergruppenführer or full General, being Himmler's deputy and even nursing ambitions to succeed Hitler himself.
Basically Heydrich made every effort to take over the Abwehr. He maintained his friendship with Canaris for the purpose of spying on him and his department. He looked with great disfavor on the enormous growth of the Abwehr, and the file on Canaris began to grow. According to Walter Schellenberg, the head of Heydrich's Intelligence section, in order to 'bring about Canaris' downfall at any moment." But Heydrich took care to warn his officers against Admiral Canaris as 'an old fox to be treated with great caution.'
Canaris' response was to obtain photocopies of evidence showing Heydrich's Jewish ancestry, and putting them in safekeeping abroad in 1941. Information of this kind on Hitler's leading persecutor of the Jews might prove invaluable.
Only after the death of Heydrich in 1942, Canaris gained some breathing space ...
Reinhard Heydrich became one of Hitler's most ruthless Nazis, second in importance only to Heinrich Himmler in the Nazi SS organization and the principle planner of Hitler's Final Solution, the murder of Europe's Jews.
At a villa owned by the SS on the shores of a suburban Berlin lake called the Wannsee, mid-level bureaucrats from a number of Nazi agencies assembled at the request of Reinhard Heydrich. Heydrich and his boss, Heinrich Himmler, head of the SS, were in the process of assuming leadership in the "Final Solution of the Jewish Question", i.e., the murder of Europe's Jews by the Nazis.
This meeting was a part of that process, as bureaucratic coordination would be required for the massive efforts to be undertaken throughout Europe to kill the 11,000,000 Jews described in the document. The Nazis ultimately succeeded in killing six million of Europe's Jews, with hundreds of thousands already dead by the time of this meeting.
Heydrich was the speaker at this Wannsee Conference January 20, 1942 and admitted received order for Final solution from Adolf Hitler. Heydrich presided over the conference with the aid of Adolf Eichmann. The conference was attended by all high ranking officials. It began the immediate starting of the overall European Genocide.
The liquidation of those Jews who were unable to work was mentioned implicitly and later extermination of the remainder was mentioned explicitly. The production of liquidation camps began such as Belzec, Sobibor and Treblinka. The vast amount of concentration camps produced after this conference made the Jewish question clear.
Reinhard Heydrich took cynical delight in forcing the Jews themselves to partially organize, administer, and finance the Final Solution through the use of Jewish councils inside the ghettos.
By mid 1942, mass gassing of Jews using Zyklon-B began at Auschwitz in occupied Poland, where extermination was conducted on an industrial scale with some estimates running as high as three million persons eventually killed through gassing, starvation, disease, shooting, and burning.
In 1942 Heydrich was assassinated in Prague, and so the Czechs saved their nation, but thousands of innocent Czech lives had been lost in executions. Nazi Germany destroyed an innocent Czech village - Lidice - to avenge the assassination of Reinhard Heydrich.
When the war ended, millions of Jews, Slavs, Gypsies, homosexuals, Jehovah's Witnesses, Communists, and others targeted by the Nazis, had died in the Holocaust. The Jewish dead numbered more than 6 million: about 4 million in killing centers like Auschwitz, 1.4 million in shooting operations, and more than 600,000 in ghettos.