The Schutzstaffel (SS; also stylized as with Armanen runes; ; literally "Protection Squadron") was a major paramilitary organization under Adolf Hitler and the National Socialist German Workers' Party (NSDAP; Nazi Party). It began with a small guard unit known as the Saal-Schutz ("Hall-Protection") made up of NSDAP volunteers to provide security for Nazi Party meetings in Munich. In 1925, Heinrich Himmler joined the unit, which had by then been reformed and given its final name. Under Himmler's direction (1929–45), it grew from a small paramilitary formation to one of the most powerful organizations in the Third Reich. From 1929 until Nazi Germany's collapse in 1945, the SS was the foremost agency of surveillance and terror within Germany itself and the occupied territories in Europe.