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The initial battles between the forces of Horus and the Imperium on Aegis, left both sides decimated and would have been the end of the world's part in the Horus Heresy, had the Sigillite not intervened. As unknown to Horus and the Imperium, there was a hidden resource on Aegis that the Sigillite wished to claim and ordered that the world would be conquered for the Emperor, no matter the cost. Though both battered sides were preparing to evacuate Aegis, the Imperium's forces immediately redeployed once the Sigillite's order was received from Terra; but unfortunately, Horus' forces also intercepted the message. Once they learned how important Aegis was, the traitors re-entered the battlefield as well, in order to prevent the Sigillite from recovering the world's hidden resource. As the new war between both sides dragged on, reinforcements for both sides frequently arrived and the subsequent battles resulted in thousands of deaths, that left Aegis largely devastated. Blackshields and even some of the Primarchs themselves, were drawn into the conflict and the war on Aegis became one of the most important battles in the Shadow Wars. However, despite its importance, the final outcome of the war is unknown.