Originally, this honour badge was only used by the proto-Astartes known as the Thunder Warriors, but would later be adopted by the genetically-enhanced regiments of the Excertus Imperialis and the early Terran-born Legiones Astartes as well.
As the Great Crusade entered its later stages, the Raptor Imperialis was replaced by the more common Imperial Aquila icon and it became a sigil instead worn by those Imperial troops who had personally fought alongside the Emperor.
By the latter years of the Great Crusade, this honour was usually found only amongst the more senior Terran Astartes of the Space Marine Legions who had seen significant action during the final campaigns of the Wars of Unification.
- Sigismund - Sigismund, the First Captain of the Imperial Fists Legion, was known to bear this version of the Raptor Imperialis upon the knee plate of his heavily-modified suit of Mark II Crusade Power Armour.
- The Horus Heresy - Book Four: Conquest (Forge World Series) by Alan Bligh, pg. 94
- White Dwarf Weekly 73 (20 June 2015), "Forge World - Sigismund, First Captain of the Imperial Fists"