The Phaedra Campaign was an Imperial military campaign undertaken by the Blood Angels Chapter of Space Marines on the Shrine World of Sabien, sometime during the 41st Millennium. At that time, Sabien had seen the largest loss of life to the Blood Angels Chapter since the battles of the Horus Heresy, and when the world had finally been pacified at the cost of untold expended lives, the Ecclesiarchy awarded custody of the planet to the Sons of Sanguinius as a reward for their sacrifices. The site of their desperate last stand against the enemies of mankind became a place of pilgrimage. The open space was littered with fallen masonry as far as the eye could see, shattered spars of rusted iron laid down upon the crumbling remains of columns. The remnants of architecture created in the ancient styles of Old Terra were everywhere.
Long halls and cloisters mingled with cathedral towers that once had cut the sky with their magnificence. Now, Sabien's streets were filled with drifts of fallen stone and the towers were humbled. Only a single construction still remained in the middle of the echoing square. Canted at an angle by eruptions of some long-silenced shell fire, a statue on a stone plinth kept watch on the dead city. Somehow, the figure of an angel had never once been struck in all the madness of the fight for Sabien. It remained here now, its features worn to vague shapes, as a symbol of human will.
Mephiston, Chief Librarian of the Blood Angels Space Marine Chapter had set foot on Sabien several lifetimes ago. He had been a different man then: Brother Calistarius, a mere Codicer centuries away from the events at Hades Hive that would remake him as Mephiston, Lord of Death. Yet, as much as he had changed in the intervening years, Sabien had not altered at all.
- Deus Sanguinius (Novel) by James Swallow