Scouring of Gilden's Star
Fought in 010.M31, during the battle elements of the Blood Angels fought a long and bloody campaign against the Word Bearers near the Galactic Core on the borders of Imperium Secundus. The Blood Angels proved merciless in scouring worlds which had embraced the Ruinous Powers and the teachings of the Dark Apostles of the Word Bearers. Most infamously, all seven worlds of Gilden's Star were purged. Ultimately, the battle resulted in the near total destruction of both armies.