Siege of Vraks - Imperial Build-Up: The forces of the Imperium required to assault these formidable defences would be the Imperial Guard Regiments raised from the world of Krieg: the infamous Death Korps. These were the best Astra Militarum regiments available to the Imperium. The men of Krieg were loyal, dutiful and extremely disciplined. They would fight with an almost inhuman disregard for the cost in casualties, seeing death in battle as the ultimate goal of their lives, to sacrifice themselves for the God-Emperor.The 88th Siege Army would be equipped depending on each regiment's designation. Most of the regiments would be siege regiments, equipped for a long war against static positions, with a special emphasis on artillery. Artillery was the heart of the plan for laying siege to Vraks Prime, and it would be a gunner's war. Large concentrations of heavy artillery would be needed to blast the enemy from their defensive lines, allowing infantry attacks to sweep forward in their wake. Each regiment would have its own artillery companies, with weaponry ranging from small mortars to the medium artillery of heavy mortars and Quad Launchers.There would also be heavy artillery in the form of Medusa siege guns and Earthshaker Cannons, the work-horse of the 88th Siege Army, as well as the heaviest Imperial artillery in use, the deadly Bombards. To augment each regiment's own artillery company, independent artillery regiments would be attached to the army. Other regiments would be equipped as mobile armoured regiments, but for a siege campaign the armoured regiments would be used as breakthrough and gap exploitation forces and would not expect to man the lines as the infantry and artillery regiments would. The tanks would be used to support the infantry's attacks and there would be no mass tank battles since the Imperial forces intended to deny the Heretics the chance to engage in armoured warfare. Still, Imperial Guard Leman Russes, Baneblades and Gorgons would all play their part in the siege.For the men of Krieg, Vraks would prove to be an alien environment. All of them had been raised in the underground hive cities of Krieg, where they became used to the constant overcrowding and recycled air. They had trained for battle on their world's blasted surface, amidst the frigid cold and radioactive hot spots of a perpetual nuclear winter amidst a landscape of ruined buildings and the hideous metallic mass of trench and razor wire left from the planetary civil war that had devastated their world centuries before. While many of the Death Korps regiments were well-established, they had been brought up to strength with many new recruits who had never seen combat before they set foot on Vraks Prime.Vraks was a barren world, covered in a choking layer of volcanic dust, with little vegetation. Its climate was warmer than that of frigid Krieg, but violent electrical storms were a daily problem, as were the sudden downpours that accompanied them. These storms turned the ground into a churning sea of sticky grey mud as the water drained away into Vraks Prime's dusty surface. The battlefield encompassed the whole of the planet's Van Meersland Wastes, 5,000 square kilometres of dusty, rocky plains with the occasional outcropping of volcanic rock. The defenders knew this terrain well, but the forces of the Emperor would have to learn the nature of the battlefield as the siege progressed.The Fortress of Vraks, also called the Citadel, housed the headquarters of the Vraksian Planetary Defence Forces, the Master of the Administratum's offices, the great Basilica of Saint Leonis the Blind, the Cardinal's Palace and the Citadel's own garrison barracks. By the time the Imperial siege of the world began, 3 defensive lines had been constructed to the north, west and south of the Citadel by the rebel forces, with the rest of the area to the south and east defended by gorges and canyons, rendering it unsuitable for a massed attack. At the time of the uprising, work had not been completed on the outer defensive lines, providing the Death Korps' forces a target for the first strike against the Heretics' fortress when they finally arrived on the world in 812.M41.