The Night of the Long Knives (German: Nacht der langen Messer [ˈnaxt dɛɐ̯ ˈlaŋən ˈmɛsɐ] ), also called the Röhm purge or Operation Hummingbird (German: Aktion Kolibri), was a purge that took place in Nazi Germany from 30 June to 2 July 1934. Chancellor Adolf Hitler, urged on by Hermann Göring and Heinrich Himmler, ordered a series of extrajudicial executions intended to consolidate his power and alleviate the German military's concerns about the role of Ernst Röhm and the Sturmabteilung (SA), the Nazis' paramilitary organization, known colloquially as "Brownshirts". Nazi propaganda presented the murders as a preventive measure against an alleged imminent coup by the SA under Röhm—the so-called Röhm Putsch.
The primary instruments of Hitler's action were the Schutzstaffel (SS) paramilitary force under Himmler and its Security Service (SD), and the Gestapo (secret police) under Reinhard Heydrich, which between them carried out most of the killings. Göring's personal police battalion also took part. Many of those killed in the purge were leaders of the SA, the best-known being Röhm himself, the SA's chief of staff and one of Hitler's longtime supporters and allies. Leading members of the Strasserist faction of the Nazi Party, including its leader Gregor Strasser, were also killed, as were establishment conservatives and anti-Nazis, such as former Chancellor Kurt von Schleicher and Bavarian politician Gustav Ritter von Kahr, who had helped suppress Hitler's Beer Hall Putsch in 1923. The murders of SA leaders were also intended to improve the image of the Hitler government with a German public increasingly critical of thuggish SA tactics.