In 1936, Heydrich learned that a top-ranking Soviet officer was plotting to overthrow Joseph Stalin. Sensing an opportunity to strike a blow at both the Soviet Army and Admiral Canaris of Germany's Abwehr, Heydrich decided that the Soviet officers should be "unmasked".  He discussed the matter with Himmler and both in turn brought it to Hitler's attention. But the "information" Heydrich had received was actually misinformation planted by Stalin himself in an attempt to legitimise his planned purges of the Red Army's high command. Stalin ordered one of his best NKVD agents, General Nikolai Skoblin, to pass Heydrich false information suggesting that Marshal Mikhail Tukhachevsky and other Soviet generals were plotting against Stalin. Hitler approved Heydrich's plan to act on the information immediately.  Heydrich's SD forged documents and letters implicated Tukhachevsky and other Red Army commanders. The material was delivered to the NKVD.  The Great Purge of the Red Army followed on Stalin's orders. While Heydrich believed they had successfully deluded Stalin into executing or dismissing 35,000 of his officer corps, the importance of Heydrich's part is a matter of speculation and conjecture.  Soviet military prosecutors did not use the forged documents against the generals in their secret trial; they instead relied on false confessions extorted or beaten out of the defendants.