The Gehenna Campaign was conducted by Lord Commander Dante, Chapter Master of the Blood Angels Space Marine Chapter and its 3rd Company in 955.M41. They battled against the Necron legions of Szarekh, the Silent King, amidst the dusty wastes of the Hive World of Gehenna.
For three weeks, neither side could seize the upper hand, with Dante's tactical brilliance stretched to its limits in countering the time-space manipulations of the Silent King. The stalemate was broken only when a Tyranid splinter fleet entered orbit, forcing the two armies to break off hostilities and fight the common foe. The impromptu alliance proved to be the Tyranids' undoing.
Following the final battle at Devil's Crag, Dante and the Silent King went their separate ways, both forces too battleworn to guarantee victory over the other, and, at least for the Blood Angels, the idea of turning on those they had so recently fought alongside proved a rather distasteful one.
- Codex: Blood Angels (5th Edition), pg. 16