The Cult practiced the ritualistic teachings of the legendary Hermes Trismegistus, who may have been a mortal mage or even the god Hermes himself. Their magic was worked in concert, with hundreds of priests, acolytes and initiated magi across several cities. While not one of the most powerful religious cults of the Empire, at its height, even a number of senators were counted among them. As Rome expanded the bounds of its empire, the cult came into conflict with "barbarian" mages on the outskirts of the empire, such as the predecessors of the Verbena. While the magic of the Mercurists was entirely ritualistic and had more in common with Linear magic than Awakened arts, the magician Plentarch codified numerous rituals into a catalogue of thirty-eight proto-Spells that were going to be used by its standard members. Impressive for its time, the Cult accepted converts from every part of the Empire and tried to incorporate foreign traditions to be best of their abilities.
Since the Cult of Mercury required so many dedicated priests to cast even a single spell, as well as broad financial support for the ritual components, it lost much of its power as Rome decayed. The cult fragmented as different groups of priests chose different sides in the civil wars, and by A.D. 300, most of its stronger spells could no longer be cast, because of the lack of cooperating priests. When Christianity became the official state religion, the Cult of Mercury was forced to abandon its temples and had to practice its craft in secret. The cult finally disintegrated after the fall of the Western Roman Empire, but their teachings were rediscovered by the mage Bonisagus centuries later. Bonisagus went on to spread this lost knowledge among any and all European mages who would listen; the fellowship that emerged from this shared knowledge became the backbone of the Order of Hermes.
A small revivalist force of Sorcerers has tried to revitalize the Cult, researching its magic to the best of their abilities.
- The symbol of the Cult of Mercury was a roman Aquila grasping a caduceus within its talons.
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- , p.96-98
- , p.137