This was a simple adjustment (since the core premise of both settings is 'Earth as we know it' + 'supernatural fiction is reality') and particularly suited to the 'Tremere connection' between a clan of vampires from the original Vampire and a House of magi in the Order of Hermes (the central organization of Ars Magica as well as one of the 'Traditions' in M:TA).
Order of the British Empire | Order of Australia | Law & Order | Order of the Bath | Order of St Michael and St George | Dominican Order | Royal Victorian Order | Law & Order: Special Victims Unit | Distinguished Service Order | Order of Canada | Order of the Garter | New Order | Hermès | Order of Saint Benedict | Order of Friars Minor Capuchin | Order of the Crown of Italy | order | Independent Order of Odd Fellows | Hermes | Royal Guelphic Order | Law & Order: Criminal Intent | Order of St. Olav | Order of St. Gregory the Great | Venerable Order of Saint John | Order of the Star of India | Corinthian order | Order of the Indian Empire | Order of the Rising Sun | Order of St. Anna | Order of the Polar Star |
Standard player-character Magi belong the Order of Hermes, a society of magically "Gifted" humans founded in 767 A.D. by the witch Trianoma and magus Bonisagus after the latter developed a breakthrough in communicating and manipulating magic (termed 'Hermetic Magic' for its roots in both the Greek deity Hermes, upon which the ancient Roman Cult of Mercury was based, and the works of the legendary figure Hermes Trismegistus).