Carnage of Morox
Fought from 009.M31 all the way to 053.M31 (into the Great Scouring), it was one of the largest confrontations between Loyalist and Traitor-aligned Imperial Army forces. Both sides sought control of the Sector capital world of Morox Excellus. Due to turbulent Warp Storms, the sector was largely isolated from the rest of the Galaxy and the war was fought with little outside interference. Despite the lack of strategic significance for the wider conflict, it was noted for its massive level of atrocity and rapid technological regression by both sides. Ultimately, 3 billion battlefield deaths were recorded.