Blood Ravens - Era Indomitus: Before the Imperium was torn asunder by the birth of the Great Rift and wracked by the Noctis Aeterna that marked the dawn of the Era Indomitus, the Blood Ravens were still reeling from the horrendous casualties and internal strife suffered during the Acheron Campaign, the three Aurelian Crusades and the Kaurava Campaign.With the Chapter barely at half-strength in the wake of these conflicts, Gabriel Angelos ordered a regrouping and rearming in Sub-sector Aurelia, and the bulk of the Blood Ravens were able to return. The Chapter Master decreed that this consolidation was to be conducted alongside large-scale recruitment. Blood Trials to find new aspirants were carried out on every world from which the Blood Ravens recruited, and they were held more frequently.Production of arms, starships, and other war materiel increased. Angelos declared that, once enough of the Chapter had been rebuilt, the Blood Ravens would strike out into the galaxy anew and bring bolter and blade to the Emperor's foes with renewed vigour. But this grand rebuilding was not to be. Scant solar weeks after initiating his plans, madness erupted in the sky as the Cicatrix Maledictum emerged and the Astronomican dimmed and flickered out. Contact between the Blood Ravens detachments conducting Blood Trials and the Chapter's flagship Omnis Arcanum became next to impossible.Ships full of aspirants were lost to the Warp. All over Sub-sector Aurelia, outbreaks of mutation and other psychic phenomena were endemic. Some Blood Ravens, psychically sensitive as many are, perished or were driven to madness by the surge in empyric energy.Those Librarians able to make some sense of the distortion reported terrible visions and nightmares, some even of the Great Unclean One Ulkair stirring in his prison in the core of old Aurelia. Entire astropathic choirs died horrendous deaths as uncontrollable forces built up inside them to the point that their heads literally exploded under the expanding pressure.Despite all of this, enough psychic infrastructure remained intact for scores of desperate messages to reach the core of the Blood Ravens fleet, each begging for the Chapter's aid as worlds across the length, breadth, and depth of Sub-sector Aurelia found themselves beset by Daemonic onslaughts, mass outbursts of mutation, and rising heretical xenophile and Chaos Cults.Gabriel Angelos, ever a warrior of honour, nobility, and an uncompromising stubbornness in the face of the enemy, ordered his Blood Ravens to respond to as many worlds as possible within the region. Due to the loss of the Astronomican's beacon, carrying out such commands was much easier said than done. But the Blood Ravens persevered, rushing as quickly as they could to their allies' aid using short, arduous Warp jumps.Throughout this time, Angelos had his astropaths endeavour to send messages across the Great Rift -- what the Blood Ravens called the "Tear" -- to what they would later know to be the Imperium Sanctus. Several ships were also dispatched across the Great Rift. None of the attempts were successful and countless brave lives were lost.It was only when elements of the Adeptus Custodes' Emissaries Imperatus located the Blood Ravens 7th Company -- under the command of Captain Atanaxis -- that the Chapter regained any contact with the wider Imperium. In a tense meeting, the Custodes stated that Primarch Roboute Guilliman had returned to lead the Imperium in its darkest hour as its lord commander and Imperial Regent. They also explained that what they called Primaris Space Marines were fighting for the Imperium in the tens of thousands.Bringing with them supplies of the Blood Ravens' own gene-seed sourced from the vaults of Mars themselves and modified by the tech-priests of Archmagos Dominus Belisarius Cawl, the Custodes presented Atanaxis with a gift from the Emperor -- the means to develop Primaris Space Marines of their own. Eager to learn what this might mean and what knowledge of the Chapter's origins they could yield from this, Captain Atanaxis accepted, though what real choice he had in the matter is debatable.Many Terran years later, with the Indomitus Crusade in full swing and its fleets rushing to the aid of beleaguered star systems across the galaxy, hundreds of Primaris Space Marines clad in Blood Ravens colours now wage war in the Emperor's name. Armed with all the new panoply of war created by Belisarius Cawl, they bring death to their enemies across Sub-sector Aurelia and beyond, their forces combatting the malignant hordes of the Archenemy wherever they find them, be they clawing their way out of the Storm of the Emperor's Wrath, or laying siege to the Somnium Stars.Using their talents for research, the Blood Ravens' Apothecaries and Librarians applied every kind of scrutiny known to them to the new gene-seed and Primaris creation technology provided for them by the Adeptus Mechanicus. What they might have discovered is naught but suspicion and conjecture to any outside the Chapter who know of the Blood Ravens' deep desire to seek out knowledge of their origins.The Secret Masters in particular have made a point of ensuring that the knowledge they have gleaned remains secret, going to great lengths to secure it against any eyes that might pry where they are not welcome.