Original: The Waffen-SS, the combat branch of the SS (the Nazi Party's paramilitary organization), became the de facto fourth branch of the Wehrmacht, as it expanded from three regiments to 38 divisions by 1945.
Simplified: Article 47 of the Weimar Constitution of 1919 declared "Der Reichspräsident hat den Oberbefehl über die gesamte Wehrmacht des Reiches" (meaning: "The Reichspräsident holds supreme command of all armed forces of the Reich").