In 742.M41 the Union Heretek Jagerdamen began a search for an artefact of unholy power. This led him to the Cemetery World Agusia, where the Union and their Eldar Corsair allies, the Cabal of the Bloody Libation, searched for the artefact. However the pirates were betrayed by one of their own and this allowed a combined Rogue Trader fleet to ambush the Union and Cabal. This began the Battle of Agusia and both sides took heavy losses after 15 hours of battle. However, the tide turned against the Union and their station-sized mothership broke apart while attempting to flee into the Warp. The Union were destroyed by the end of the battle and the mauled Libation Corsairs scattered into the void.