"For our Faith, and the Light of the Throne!
Battflefleet Valkyre is stationed in the Valkyre system of the Segmentum Ultima, close to the border of Segmentum Obscurus. Founded in the earliest days of the Imperium, Battlefleet Valkyre has a long and proud history of Naval service, having risen from very humble beginnings. No world of the Valkyre system is capable of supporting life, and Valkyre itself is a gas giant, but its value as a fuel refinery and trade hub saw the construction first of a small military port, and then later fabrication docks. This escalated over the millennia, eventually producing modern Valkyre; a vast sphere of interconnected gas mines, orbital habitations, naval dry docks and weapon platforms. Her berths house thousands of vessels and innumerable attack craft; only the greatest of shipyards, such as Mars or the Segmentum Headquarters can hope to rival Valkyre, and vessels are produced from the system for use across the Imperium.
Mastery of the Skies:
The Valkyran forces, having been born on a world with no natural solid ground, are naturally gifted in the arts of naval warfare. While its naval fleet is a force of which Valkyre is rightly proud, it is the attack squadrons that truly cement its reputation. Valkyre is a world of fighter aces; Starhawks bearing the White Aquila have spelt the doom of thousands of ships, and on planets all across the Imperium the enemies of Man have cried out in terror as Thunderhawks and Marauder Bombers raised from this world have brought Imperial wroth upon them.
This innate gift for aerial supremacy has influenced the doctrinal choices of Battlefleet Valkyre. They heavily favour the use of carriers, which can make up half or more of any given battlegroup. Unsurprisingly, the Emperor Class Battleship is considered an iconic vessel among Battlefleet Valkyre, and the few they are fortunate enough to possess are treasured relics. The Fleet has also fought heavily against the shifting tastes of the wider Imperial Navy, actively drawing and maintaining older carriers, such as the Mars or Styx class for their own use.
The Faithless Night:
Valkyre has been threatened many times by many foes, but the taint of Chaos has always been their greatest fear. From the early days of the Heresy, the Valkyrans have known the Archenemy have sought to control their resources and ships.
No event showed this more clearly than the Faithless Night. In the wake of the Age of Apostasy, a time when all across the Imperium men and women sought to reassert their loyalty to the God-Emperor, Valkyre Sector became overwhelmed with pilgrim ships and travelers, all hoping to refuel and make good before journeying on. Tens of thousands of slow, lightly armed ships was far too tempting a target, and across the Sector raiders, both Human and Alien alike, became emboldened. Battlefleet Valkyre was stretched to breaking point trying to run convoy duties and hunt down pirate bases, and in all this confusion an unassuming flotilla of ships came to Port Valkyre seeing respite.
It is impossible to know where the Taint came from, or for how long it lingered aboard those ships, but it passed undetected until it was too late. At the start of the dawn shift, the pilgrims began to transmit a distress signal, reporting they were under attack from an enemy warship. Rapid response vessels confirmed the assailant to be Black Death, a Chaos vessel from the days of the Horus Heresy.
At once, the reserve fleet sprang into action. The newly constructed Despoiler Class Dragon, supported by the Styx Pride of Ultima and three other line cruisers all broke moorings and began a full burn after Black Death, seeking to catch and kill this long hunted quarry.
The initial battle waged for the better part of a day; a running battle where Black Death made repeated sweeps toward the pilgrims, only to dart away as the Imperials tried to bring her to battle. As the second day began the Imperials had lost more than a dozen escorts and three light cruisers, but they had at last begun to inflict telling blows upon the Chaos craft and most of the pilgrim ships had survived.
Yet as the pilgrims passed close by their would-be protectors, Black Death charged again. As their master's ship drew near, all crew and passengers committed ritual suicide. The psychic power of nearly half a million souls passing as one energised the Warp-tainted lord of Black Death, and the ship unleashed a Warp blast that spread madness and corruption throughout the Imperial fleet. In that moment, Black Death transformed into a Daemonship and led its enslaved fleet to strike the port.
The battle that followed was catastrophic for Valkyre, and almost spelled the end for the planet. Many of their finest aces had now become servants of Chaos, and their most powerful ships were now either out of system or in the hands of the enemy. As Black Death began broadcasting its unholy signal, other ship crews and stations hands began to turn. Port Valkyre tore itself apart in a maelstrom of aerial dogfights and fleet skirmishes.
Salvation came from an unexpected source; heeding omens from their Librarians, the Fate's Angels Space Marine Chapter launched an assault of their own into Port Valkyre, hurling their entire fleet toward Black Death. Although suffering heavily losses, the Astartes crippled the Daemonship and forced it to retreat into the Warp. With their daemonic master gone some of the madness receded, but it was far from over. Many men were now too far gone, or had done actions that could not be forgiven. For many years the remnants of Battlefleet Valkyre would seek purge itself of this dark taint, reforging itself as a shining symbol of Imperial Faith.
Sadly, the fates of many Traitors are ultimately known, and Black Death herself remains at large. However, in the five millennia since that terrible day, not a single vessel of Valkyre has been swayed by the ruinous powers.