Battle of the Corollis Star
After a period of failing to bring the Diasporex to battle, a plan was finally agreed upon by the Primarch's Fulgrim and Ferrus Manus to attack their fuel convoys orbiting the Corollis Star. Sure enough, the Diasporex fleet was forced to show itself finally and a pitched void war began after a hasty assault by Ferrus' Iron Hands which Fulgrim felt was reckless and robbing him of his own deserved glory. The Diasporex Fleet was large and well equipped, with ships that could take over the systems of Imperial vessels and force them to turn on their allies. However the multi-species, multi-cultural, democratic nature of the fleet prevented them from coordinating themselves properly. After the loss of the Battle Barge Metallus the Diasporex vessels attempted to flee through the gap formed in the Iron Hands formation, but were cut off by the newly arrived Emperor's Children ships under Fulgrim.
As the battle in space raged, it became clear that some semblance of coordination was being setup by the largest Diasporex vessel, a human-xenos hybrid command ship. Fulgrim led a boarding operation of this ship, massacring all human and xenos they came across within. After a brief but fierce boarding action in which Solomon Demeter stole the glory of seizing the Diasporex ship from the Fulgrim, the battle came to an end. The final words of the alien captain were "We only wished to be left alone".