The SA was the original paramilitary formation of the NSDAP, being founded in 1921 at a Hofbraehaus beer hall rally in Munich and used to both defend the NSDAP as well as attack other political parties. The SA was composed mainly of members of the various Freikorps formations and unemployed men. It was named after an elite division of the German Army from the 1st World War

The Storm Troops or "Brownshirts" were organized initially to serve as a protective force at Nazi Party meetings and placed under the leadership of Captain Ernst Röhm who was very important to Hitler in the early days of the NSDAP party. The SA exploded in size from an embryonic 46-man detachment to a massive organization claiming in excess of four million members in 1934, 40 times larger than the Army. Its purpose was to ensure that the parties policies, actions and idea's were not hindered or restricted in any way. Its main method of implementing these actions was by force, violence and intimidation.

During this time frame, both the SS and NSKK were organic branches of the SA.

The SA leader, Captain Ernst Rohm, wanted to arm the SA and to integrate the Army within his authority. Without Hitler’s authority, Rohm started to talk about a "second revolution" where the bourgeois of the party and Army would be swept away and a new order appear.

Eventually Hitler decided to end the way in which the SA was organised as he considered the SA and Ernst Rohm a threat to the further expansion of his policies. As a result, Hitler instigated the "Night of the Long Knives" blood purge to weaken the SA leadership and its power. Hitler used Himmler and his SS to bring about the fall of Rohm and his fellow SA leaders, about 300 senior SA members and other political enemies of the NSDAP party were killed.

After this purge the SA was less important to Hitler due to his planned expansion of the Army, which after the purge and his promise of expansion, felt Hitler was their true friend. As a result of the purge, Himmler and the SS became Hitler’s new means of controlling the Party and the German people.

After the "Blood Purge" of Ernst Röhm and SA leaders in 1934, Victor Lutze was appointed SA Stabchef (Chief of Staff) and retained the position until 1943, when he was killed in an automobile accident. Wilhelm Schepmann succeeded Lutze.

During the war years, the SA was charged with the pre and post-military training of German manpower in co-operation with the heads of the military services. The German Armed Forces drew much needed replacement personnel from this group, and by 1944-45 over 85% of the SA had seen active military experience.