The first Sturmschutz regiments were created from veterans of the Wehttam Defense Forces to fight in the Great Crusade in service to the Emperor. These regiments fought in support of the Space Marine Legions in the campagin of conquest under the command of the Sons of the Emperor, the Primarchs. The Sturmschutz were orgianized as part of three Space Marine Fleets and participated in the the bloodiest battles of the campaign earning a fearsome reputation for valor and discipline on the battlefield. The determination and prowess of the Sturmschutz in combat earned them respect and honor across the Imperium even amognst the ranks of the Space Marines.