Herr Adolf Hitler, the German Chancellor, has saved his country. Swiftly and with exorable severity, he has delivered Germany from men who had become a danger to the unity of the German people and to the order of the state. With lightening rapidity he has caused them to be removed from high office, to be arrested, and put to death.
The names of the men who have been shot by his orders are already known. Hitler's love of Germany has triumphed over private friendships and fidelity to comrades who had stood shoulder to shoulder with him in the fight for Germany's future.
~Daily Mail, July 2nd 1934.
Hitler posing with SA members in the late 1920s.
Hermann Göring stands bedecked
with medals beneath Hitler.
When Hitler rose to power in early 1933, he owed much of his success to the muscle of his Nazi Storm Troopers (wiki), the SA (Sturmabteilung), a violent, ruthless army headed by Ernst Röhm, Hitler’s long-time friend and devotee. Röhm and his Storm Troopers brought Germany into submission by gaining control of the streets gangster-style and violently eliminating any of Hitler’s political enemies.
By the summer of 1934, the SA's numbers had swollen to 2 million men. The SA had given the Nazis an iron fist with which to disrupt other political parties' meetings before Hitler became Chancellor in January 1933, and was also used to enforce law afterwards: essentially, they were the enforcers of the Nazi Party.
|Hitler and Rohm, 1933|
Hitler knew that the army hierarchy held him in disdain as he was 'only ' a corporal in their eyes, and the regular army hierarchy also saw the SA as a threat to their authority. The SA outnumbered the army by 1934 and Röhm had openly spoken about taking over the regular army by absorbing it into the SA. Such talk alarmed the army's leaders, and in April of that year, Hitler and the head of the German army, Werner von Blomberg, signed a secret agreement in which Hitler promised Blomberg’s army absolute control of the military (with precedence over the SA); and von Blomberg pledged the army’s backing when Germany’s 86-year-old president Paul von Hindenburg inevitably shuffled off the mortal coil and Hitler claimed the presidency.
When Hitler met with German President Paul von Hindenburg on June 21, 1934, the old man was in very poor health and was confined to a wheelchair, but his mind was sharp as ever. He brusquely informed Hitler and Defense Minister Blomberg that the SA must be brought to heel ASAP, or he would declare martial law in Germany and let the army run the show, which would pretty much mean the end of the Nazi party.
Night of the Long Knives (wiki), Hitler made his move. In the village of Bad Wiesse, the SS raided a hotel where Röhm and his buddies were hanging out for the weekend. Members of the SA were dragged from their beds and executed on the spot.
Just before Wiessee, Hitler suddenly breaks his silence: "Kempka", he says, "drive carefully when we come to the Hotel Hanselbauer. You must drive up without making any noise. If you see a SA guard in front of the hotel, don't wait for them to report to me; drive on and stop at the hotel entrance." Then after a moment of deathly silence: "Röhm wants to carry out a coup." An icy shiver ran down my back. I could have believed anything, but not a coup by Röhm.
~Kempka, I Was Hitler's Chauffeur
The SA was brought to heel and placed under the command of the army. The Night of the Long Knives not only removed the SA leaders but also got Hitler the army's oath that he so needed.
The first the public officially knew about the event was on July 13th 1934, when Hitler told the Reichstag that met in the Kroll Opera House, Berlin, that for the duration of the arrests that he and he alone was the judge in Germany and that the SS carried out his orders.
“If anyone reproaches me and asks why I did not resort to the regular courts of justice, then all I can say is this: In this hour I was responsible for the fate of the German people, and thereby I became the supreme judge of the German people.”
~Adolf Hitler, July 13, 1934
From that time on the SS became a feared force in Nazi Germany, lead by Heinrich Himmler. The efficiency with which the SS had carried out its orders greatly impressed Hitler and Himmler went on to acquire huge power within Nazi Germany.
Here's a brief Khan Academy video describing the event:
History channel 4 minute video: