Core Worlds Campaign

Core Worlds campaign
Date	998.M30
Scale	Sector-wide
Theatre	Chelob Hold Sector
Status	Decisive Imperial Victory
Belligerents
Imperium of Mankind	Core Worlds Confederation
Commanders and Leaders
Gaspard Lumey and Uriel Starikov	various Core Lords
Strength
over 100,000 Space Marines, 1.5 million Imperial Army, significant Imperial Navy support	estimated between 4 million and 12 million ground forces, limited space presence
Losses
9,842 Space Marines (6,106 Winged Victory, 3,736 Children of Armok), roughly 140,000 Imperial Army	tens of billions
Outcome

While the Emperor and Hektor confronted the Ork Empire of Ullanor, another potential thorn in the side of the Imperium was making its presence felt. The mighty Core Worlds Confederation, the largest and most advanced human realm outside of the Imperium, had long pursued a policy of peaceful co-existence. The Core Lords were perfectly happy to open their borders to Rogue Traders, shared civilian technologies with the Tech Priests of Mars, and occasionally permitted their vassals to participate in the Great Crusade as mercenaries. But they had refused to entertain the Emperor's demand for human unity across the galaxy. Worse yet, their independence was beginning to inspire worlds that lay outside the Imperium's grip to stand independent while some of those that had only recently been pacified began to lobby for a looser form of government and more regional authority. Gaspard Lumey and Uriel Starikov were dispatched to resolve the matter one way or another.

Initially, the Primarchs attempted a negotiation. However, they ran into two fundamental problems. Firstly, while the Core Lords appreciated the seriousness of the Emperor sending two of his sons to treat with them, they were still reluctant to give up their autonomy and demanded concessions and guarantees. Worse yet, the decentralised nature of the Confederation saw each world competing against its fellows to get the best deal from the Imperium. As negotiations began to see-saw between ever more demanding petitions from Karazak and Chelob Hold, the two strongest Core Worlds, Gaspard Lumey walked out of the negotiations to prepare his campaign. Uriel Starikov remained only long enough to conduct the formalities of ending the talks.

Lumey opened the attack with a horrifying fleet bombardment of Karazak, the de facto capital world of the Confederation. Until the coming of the Imperial Legions, Karazak was said to rival Terra itself in its technology, industry and population. The greatest of the Core Worlds was dominated by immense underground cities and its citizens were confident that they had little to fear from a direct assault. They did not count on Lumey's resolve. The Primarch launched a horrifying fleet bombardment that fractured the crust of the planet and killed tens of billions. A petition for conditional surrender brought not relief, but the descent of the Fifth Legion. What resistance remained on Karazak was swept aside in three bloody days. On receiving news of Lumey's attack, several Core Worlds, including Karazak's old rival, Chelob Hold, immediately offered unconditional surrender to the Children of Armok. With their enemies reeling, the Primarchs pressed the initiative. The Void Angels split into three task forces, led by Gaspard Lumey and his trusted lieutenants Fabrice Diallo and Augustin Carron, while the Children of Armok, mainly committed elsewhere in the galaxy, dispatched small fleets to the weakest worlds. Lumey's force hunted down the remains of the Core Worlds fleet, capturing two great factory ships with audacious boarding actions. Diallo's men went into the tunnels of the Mining World of Lzoro, overwhelming the defenders in a bloody hand-to-hand struggle. Carron waged a lightning war down the Varrian Reach, seizing ten worlds in as many days. Each victory brought new offers of surrender as the remaining Core Lords began to see the inevitability of their fate. Yet their hopes of leniency were dashed. Lumey insisted on the execution of the surrendering aristocrats and a heavy tithe upon the newly conquered worlds. It is thought that Starikov actually talked down his imperious brother from even harsher terms, though it is hard to imagine what further punishment could have been levelled on the defeated.