The Schutzstaffel, or in other words, the Protection Squadron was a major paramilitary organization under Adolf Hitler and the Nazi Party in Germany, and later throughout German-occupied Europe during World War II. It began with a small guard unit known as the Saal-Schutz, or Hall-Protection made up of Nazi volunteers to provide security for party meetings in Munich. In 1925, Heinrich Himmler joined the unit, which had by then been reformed and given its final name. Under his direction, it grew from a small paramilitary formation to one of the most powerful organizations in Nazi Germany. From 1929 until the regime's collapse in 1945, the SS was the foremost agency of security, surveillance, and terror within Germany and German-occupied Europe. The two main constituent groups were the Allgemeine SS (General SS) and Waffen-SS (Armed SS). The Allgemeine SS was responsible for enforcing the racial policy of Nazi Germany and general policing, whereas the Waffen-SS consisted of combat units of troops within Nazi Germany's military.