Sun Angels

"Our Duty is to All Mankind and the Imperium. In the Emperor's name! For Primarch-Progenitor! Hail the Warmaster and death to all Her enemies!"-Lord Commander of the Athanatoi, Arkidamus, at the Cleansing of Ullyes XII

The Sun Angels are the Vth Legion of the Legiones Astartes raised by the Emperor of Mankind in the closing years of the Unification Wars as one of the First Founding. The Vth Legion has ever been a loyal and highly esteemed legion whom some whisper as the Emperor's Greatest. If not by reputation than certainly by scope. For no other legion has brought more worlds under Imperial Compliance, no more foes vanquished in the Emperor's name, than the Sun Angels.

Origins
The Sun Angels were a First Founding formation of the Space Marines. Originally raised from Terran stock. Its initial recruits being from the regions of Terra before the Unification War as the Magyar Empire, Skandia, Begardia, Arkhankhel, Iron Justiciarium, Khossak, Nova Jovia, and Dorogov. The initial 10,000 recruits completing their training as the Unification Wars till raged and then deployed in secret for a purpose that the nascent Imperium was best to not think about. Wars against Mutants, Psyker-Chiefdoms, and other horrors which still roamed the surface of Terra. Their numbers gradually being supplemented through successful implantation into mutant populations. For the gene-seed of the Vth was unusually stable and potent. Able to turn a horribly disfigured Terran mutant into a beautiful angelic epitome of Post-Human martial physique. Thus the Sun Angels despite their modern moniker grew in the dark and forgotten battlefields of the Unification War's closing years.

Their first recorded engagement being the Solar Reclamation. Where the Sun Angels were deployed against Pirates, Xenos, and Mutants stalking the Asteroid belt, Jovian Moons, assisting the Saturnyne Ordo, and finally the long battles on the ice moons of Neptune and Uranus.

Secret Origins
Unbeknownst to the Imperium at large, or even many of its high functionaries and leadership, the Sun Angels originally were known as The Vapir Host. A Space Marine Legion utilized by the Emperor to not only fight foes best left off official Imperial record. But to also Watch the Watchers. A Legion who could be used to attack Imperial targets deemed treasonous, unstable, or to be wiped from record and forgotten. Indeed, even the original Legion colors were different. Midnight blue with lightning iconography decorated into the armor's paint schemes. Blood red and skull motifs adorned their trimming and helmets. A horrific and ghastly foe for the enemies of the early Imperium. But, upon reunification with their Primarch and the Great Crusade underway, the Legion was repurposed to be a public icon for the expanding Imperium of Mankind. Its name, colors, and what public history available rewritten extensively. Some of which by the hand of Primarch Vasilisa and Malcador the Sigillite themselves. The Emperor of Mankind, himself, ordering any evidence to The Vapir Host be sealed in the catacombs of the Imperial Palace.

The First Primarch
Despite bearing the icon of 'V' for Fifth. The Primarch known was Vasilisa Sanguina was found first and early on. Depending on when Imperial Scholars denote the start of the Great Crusade the Primarch of the Vth Legion was discovered within two to twelve years of the Great Crusade's launch. Scout ships of the Crusades leading edge entered the outer edges of the Valtmar Hegemony. An interstellar civilization that was by then already headed by Vasilisa as 'The Golden Queen.' The Hegemony had been very close to Terra and the Emperor made all due haste to arrive. The meeting between the two was met with much fanfare and despite Imperial Remembrancer depictions as a Daughter welcoming a long lost Father it was in reality a much more formal interaction as monarch to monarch. For even though the Hegemony joined the Imperium and Vasilisa accepted the position of Primarch under the suzerain rule of the Emperor there was never a true sign of public submission. Whether by purpose or agreement only the Emperor and Vasilisa could know.