In the year 98798776, world war ten happened and destroyed the world and all of the human race. Or at least thats what would have happened if the mythical beings didn't step in and had moved a group of humans on to an island that had been under the protection of power and thus didn't get destroyed. They lived peacefully on the island with the mythical beings and knowing the truth about the world and how these lucky humans survived. Some thought the mythical beings to be gods and goddess, really the ones of great beauty.
For many years after the destruction of earth the mythical creatures left the humans alone and rebuilt London as the island was starting to get a bit crowed by then. So the vampires left first and started the building, changing out vampires who needed fresh blood every month or so. After they got it started they had the other creatures come and help build since it was still too dangerous for the humans to work.
Many years it took to build the city and for the elves and earth creatures to regrow the plants and more food for the species of the world. Once the city was safe for humans and able to feed everyone the vampires brought some of the humans to the city that they named New London.
Although it wasn't until nearly the year 600 until the city was completely finished and under the protection of vampires, werewolves, and other good creatures. As it was finished they brought the rest of the humans to the city and helped them get started in the city.
Years later around 612 AWD (after world destruction), the vampires and other creatures decided to step back and see if the human race would fix itself into the new world that they had created for the humans. Even if the "mythical" creatures still protected them from the dangers of the animals who had mutated from world war ten, they stayed mostly in the shadows again watching.
Now around the year 666AWD, the "mythical" creatures are starting to lose fame for saving the human race as some started to believe that the "mythical" creatures had started the war and planned everything. The rumors grew fast and some of the old who were trained as hunters started to take students in secret. But like everything nothing stays secret for long as one young hunter thought they could take on a vampire elder and attacked in a public place but it still ended in him being hurt badly and never able to fight again. It was then that the vampires, being the oldest out of the mythical creatures, decided it was time to take measures into their own hands and keep things looking normal like everything was fine but kept the fights to the shadows to keep peace.
Side Note: It has only been around two thousand years since the war ended.