In the spring and early summer of 1934, another complication arose. President Paul von Hindenburg, who had been giving his reluctant blessing to most Nazi initiatives, was now in failing health. Hitler had to protect his flanks. If Röhm's SA was not checked, the organization could be put to use by Röhm as the linchpin of a revolution at odds with Hitler's. However, if Röhm's leadership of the SA could be neutralized, Hitler reasoned, Germany's military establishment would endorse Der Führer as Hindenburg's successor.
Thus came to pass the notorious Night of the Long Knives, a bloodbath ordered by Hitler that ensued on June 30 and July 1. The exact number of people who were killed during this purge remains uncertain. Although some tallies put the number in the hundreds or even the thousands, probably fewer than 100 people were killed. Among them, however, were not only Röhm and other senior SA men but also conservatives who were perceived as threats to Hitler, men who might try to depose him and restore monarchy in Germany.
A key figure in the Röhm purge was Heinrich Himmler, who headed the black-shirted SS (Schutzstaffel, or Protection Squad). Initially formed in the summer of 1925 as Hitler's personal guard unit, the SS was originally part of the SA. When Himmler took command in January 1929, the SS consisted of a few hundred men. By the spring of 1934, it had already become everything that the SA was not--a disciplined, armed elite of more than 50,000 men who were intensely loyal to Hitler. At this time, Himmler's influence expanded further as he gained increasing control of Nazi Germany's political police, whose main branches included the SD (Sicherheitsdienst, or Security Service) and the Gestapo (Geheime Staatspolizei, or Secret State Police).
Once his rival, Röhm, was out of the way, Himmler reaped the benefits. For its part in the purge, his SS got independence from the SA, a move that enhanced Himmler's authority. Meanwhile, Himmler bestowed some rewards of his own. On July 4, for example, he appointed Theodor Eicke, commandant of the Dachau concentration camp, as inspector of concentration camps. Eicke, who had followed Himmler's execution order by personally murdering Röhm, instituted in other camps the systematically brutal methods of control and punishment that had characterized his administration at Dachau. With the help of Eicke and other SS subordinates, Himmler soon controlled a vast state security empire. In this capacity, Himmler would later use his SS and police power to become a key architect of the destruction of the European Jews.
While Himmler expanded his power, Hitler still had to shore up his political authority. The Röhm purge had removed threats to that authority, but it left Hitler with the need to explain what had happened and why. Hitler's strategy was to argue that Röhm and his closest SA associates were guilty of treasonous activity and sexual deviance--Röhm was a homosexual--and to portray himself as a protector whose intervention had saved good German lives.