Necessarius

is a secret branch of the Church of England that conducts supernatural and magical experiments to fight supernatural threats. Ironically, Necessarius was created by English Puritans who despise magic, but since Britain was a magical country during their time, they had to learn to use magic to counter magic. Their headquarters are located at in London. As of the start of the novels, they are allies of the Vatican and rivals with Annihilatus, the Russian Orthodox Church (ironic, as the organization's headquarters in real life is of Orthodox Denomination), but by volume 14 Necessarius, and by extension, the Church of England, ends up in an alliance with Academy City against the Roman Catholic Church. The leader of the Necessarius is surprisingly led by a young female Archbishop named Laura Stuart.