The Phoenix Guard was the elite unit of Astartes who were responsible for performing formal and ceremonial roles, serving as the Primarch Fulgrim's bodyguard during the Great Crusade and the Horus Heresy. Their number was set at 200 to commemorate the first days of the Legion's rebirth from the Emperor's Children Legion. The members of the Phoenix Guard followed their beloved Phoenician wherever he went as part of their duties, even when he was travelling within the relative safety of the starships of the Imperial Army and the vessels of the other Space Marine Legions.
During the battle to conquer the xenos world of Laeran, the Phoenix Guard took part in the final extermination of the serpentine Laer species. The entire unit was slain on the world of Tarsus in the Perdus Region of the galaxy after Fulgrim, already under the influence of Chaos through the Laer Daemonsword he had captured on Laeran, took offence at the Eldar Farseer Eldrad Ulthran's warning about Horus' corruption by Chaos, and proceeded to open fire on the Farseer and his troops from Craftworld Ulthwe.
A new Phoenix Guard was then recruited and accompanied Fulgrim during both his fateful meeting with Horus where he finally embraced Chaos and in his abortive attempt to recruit Ferrus Manus to the Traitors' cause aboard Ferrus' own flagship where they successfully slaughtered the Morlocks Terminators who served as Ferrus' own bodyguard unit. While the Phoenix Guard served Fulgrim through the Battle of Terra, it is unknown if the unit still exists and serves as the Daemon Prince's bodyguard on the unknown Daemon World he now calls home.
- Imperial Armour - The Horus Heresy - Book One: Betrayal, pg. 107
- Fulgrim (Novel) by Graham McNeill