The Sturmabteilung ("Storm Detachment"), nicknamed SA and the "Brownshirts", was the original paramilitary wing of the Nazi Party. It evolved out of the ex-soldiers and beer-hall brawlers that acted as impromptu security during Party meetings, serving as muscle against rival left-wing paramilitaries and its chief agents of voter suppression/intimidation. Its youth wing, the Jugenbund, would become the Hitler Youth. Sidelined following the murder of its leadership in 1934, it formally disbanded with Germany's capitulation at the end of World War II. While multiple SA members were complicit in war crimes and the Holocaust, the Nuremberg tribunal ultimately ruled that the SA was not itself a criminal organization.

While ostensibly anti-communist, the SA drew much of its support from the German working class and unemployed, including former Communist Party members (so-called "beefsteaks") with its leadership advocating a radical agenda opposing business elites and the aristocracy. Under Ernst Röhm, the SA replaced a decentralized command structure subordinate to individual Nazi Party regional offices with a centralized hierarchy that answered to Röhm and/or Hitler themselves. Following the Nazis' rise to power in 1933, the SA's anticapitalist stance became a liability to Hitler's industrialist backers, and Röhm's demand to absorb the Reichswehr, Germany's professional standing army, prompted distressed officers to conspire with high-ranking Nazi leaders in fabricating evidence Röhm was planning a coup. Hitler ultimately agreed to purge the SA leadership in the summer of 1934 after President Hindenburg threatened to impose martial law over continued instability.

Afterwards, the Sturmabteilung's position was diminished in favour of the SS. It was the chief instigator of Kristallnacht, but by 1939 was rendered a training school for the armed forces, with most of its members recruited for the war effort. In 1941, to combat independent SS foreign policy influence that culminated in the SS and Wehrmacht backing opposing sides in the Romanian Legionnaires' Rebellion, the Foreign Office appointed SA personnel to serve as ambassadorial staff and "quasi-Reich governors" in allied Eastern European countries.