The Adeptus Custodes, known as the Legio Custodes during the Great Crusade and Horus Heresy eras, is the Imperial adepta responsible for protecting the Imperial Palace and the physical body of the Emperor of Mankind, as well as serving as His most important emissaries, His companions, and the keepers of His many secrets. The Custodes is an elite cadre of genetically-engineered transhuman warriors who are even more potent in combat than the Adeptus Astartes. They are to the Space Marines as the Emperor is to His primarchs, and it is rumoured that they were each created by the Master of Mankind personally.