After the invasion of Poland in 1939, Reichsführer-SS Heinrich Himmler sought to expand the Waffen-SS with foreign military volunteers for the "crusade against Bolshevism". The enrollment began in April 1940 with the creation of two regiments: the Waffen-SS Regiment Nordland (for Danish, Norwegian, and Swedish volunteers), and the Waffen-SS Regiment Westland (for Dutch, and Flemish volunteers).[2]