Her Majesty Elizabeth, Queen of England, secretly established in 1560, the second year of her reign, the Arcane Service. The Service is composed of people, usually but not solely of magical bent, who have sworn to protect the realm from magical assault. The head of this service is Dr. John Dee, the Queen’s Astrologer, and noted Savant.
He finds agents for his Service by listening to the advice of the angels, who speak to him from a peculiar mirror he has installed in his rooms, which he keeps covered in cloth when not consulting it. He has a long, pointed beard, and wears a skullcap over his thinning hair.
The player characters are assumed to be agents of Doctor Dee. They are people passionately devoted to the welfare of England, and of the Queen, and unafraid of dealing with magical creatures and powerful workers of magic.
At times they may be performing political missions, perhaps in other lands, perhaps in England. At other times they will be defending the realm from magical assault from foes domestic and foreign. They can function as spies, as diplomats, as magical assault squads, and as investigators - Doctor Dee is not picky about such quibbling differences.