Maximus Octavian Grüber III - Fall of Cadia: Prior to the Fall of Cadia, Grüber had served in the Deucalion Crusade, which was among the many campaigns he had fought in his hundred-and-fifty-standard-year career in the Astra Militarum. However Grüber had ascended on the backs of the countless Cadian Guardsmen he had sent unnecessarily to their deaths and he had little compunction about wasting lives if it meant advancing his own ambitions. When Cadia was invaded by the forces of Chaos during the 13th Black Crusade, Grüber was a member of the Cadian high command and led the Astra Militarum's 17th Army from an area known as Bastion 8.As the invasion wore on, Grüber was one of the few Imperial general officers to still command his given region, which he did with discipline, a stubborn lack of imagination and thirty miles of minefields. However he was forced to leave Bastion 8 when Lord Castellan Ursarkar E. Creed ordered a massive counter-attack against the Chaos invaders. This counter-offensive irritated Grüber, as he was not sure he could successfully lead his forces in the series of attacks that was asked of him. Worse, he feared that ever since the lowborn upstart Creed had became Lord Castellan of Cadia, his charisma and military genius had changed the way Cadians expected to be led. Grüber knew it was no longer enough for him to be authoritative, professional and stern. His Guardsmen now looked for him to inspire them like Creed had, but though he tried, Gruber simply lacked his rival's charisma and he was forced to repeatedly use Creed's name to keep up their enthusiasm and excitement for the campaign to come.During the planned counter-attack, Abaddon the Despoiler unleashed the remains of his Blackstone Fortress the Will of Eternity to descend like a meteor, striking the surface of the Fortress World and dooming it in the cataclysm that followed. The Imperial forces were ordered to evacuate before Cadia was rent apart by tectonic instability. In the mass panic and confusion that followed, Grüber stayed to personally supervised the evacuation of most of his forces. But once their window to escape began to close, he agreed to board the last evacuation craft and joined the Imperial fleet as it began its escape from the Cadian System.Stationed aboard Captain Zabuzkho's Claymore-class Corvette, the Lord-Lieutenant Berwicke, Gruber sent messages to the Imperial fleet to find Creed, so that the Lord Castellan could take command of the surviving Cadian Guardsmen. However Creed could not be found amongst the Imperial fleet and no one knew if he had even escaped from Cadia. Hearing this made Grüber weary, for even though he had seen Creed as a political rival, the general knew the Cadian Shock Troops needed the Lord Castellan's leadership now more than ever. They had been broken by their defeat and the shame of failing to save their beloved homeworld hung heavy on the survivors' shoulders. They needed an inspiring leader to rouse their spirits and help reforge them into an army once more. Yet without Creed, that heavy responsibility now fell to Grüber. The general knew he was not up to the task, but he was the highest-ranking general officer of the Cadian High Command to have escaped the world's fall, so he did his duty and took direct command of all the surviving Cadian Astra Militarum forces.Even as the remains of the Cadian fleet sped towards safety, Grüber began rebuilding the surviving Cadian Shock Troop regiments in an attempt to restore some level of combat-readiness. He promoted individual troops of merit to new ranks to fill the gaping voids in many of the regiments' orders of battle. As the commander of the Cadian Shock Troops, Grüber was offered passage aboard the Grand Alliance, the flagship of Battlefleet Cadia's commander Admiral d'Armitage, which would better guarantee his safety, but Grüber refused the offer since he would be required to leave his forces aboard the Lord-Lieutenant Berwicke. It was during this frantic time that Grüber met with General Isaia Bendikt so they could discuss their destination. Grüber offered that with Cadia gone, its Guardsmen must now go and defend Terra from a possible Chaos invasion. But Admiral d'Armitage claimed that with the Warp now in turmoil as a result of the Great Rift's birth, it was not likely the remains of the Cadian fleet would be able to escape the Cadian System.Grüber refused to accept this, and met with the fleet's best surviving Navigator, Hyppolytus Fremm, in an attempt to find a solution. Fremm echoed d'Armitage's claims about the difficulty of navigating through the turmoil of the Warp and the Navigator claimed Cadia's death throes had caused the Immaterium to roil in a way he had never seen before. Fremm explained to a frustrated Grüber that to attempt to reach Terra in those circumstances would result in the deaths of every man and woman in the fleet. But Grüber insisted that Fremm keep trying to enter the Warp and the Navigator eventually succeeded in guiding them out of the Cadian System, just as Chaos warships closed in on the Cadian fleet.When the Lord-Lieutenant Berwicke emerged from the Warp, however, it was apparent something had gone wrong within the spiraling currents of the Sea of Souls. Instead of Terra, men and women of the Cadian fleet saw the Forge World of Agripinaa before them and only a few vessels of the Cadian fleet had appeared beside the Berwicke. A furious Grüber went to confront Fremm, but stopped when he saw how close to death the Navigator was. The effort of guiding the fleet through the turmoil of the Warp had severely drained Fremm and he apologised, for the nearby Agripinaa System was as far as he had been able to guide the fleet before his mind gave out from the strain.While Grüber was troubled that most of the Cadian fleet seemed to be missing, Fremm told Grüber that it was likely that the rest of the Cadian warships had emerged elsewhere in the system, though he did not know if they were close by. Grüber's small fleet of ships began to make their way to Agripinaa and Grüber hoped to send word of the Fall of Cadia to the High Lords of Terra. Still, Grüber being Grüber, he also hoped to convince the High Lords that the Imperium could not function without the Cadian Shock Troops in an attempt to avert any blame for the fall of the Fortress World that the members of the Imperial Court might try and pin upon the Cadian survivors.Yet before the small Cadian fleet could reach the Forge World, they were ambushed by the waiting Chaos fleet of Agitor Kanath, a Chaos Lord of the Sons of Malice Heretic Astartes.