There is fine line in historic fantasy when you are playing with the lives of real people.
We fit the story into their real lives as much as possible. Bram and Oscar had both moved to London early in their careers and the story takes place before they are famous. We slip in the vampires and fantasy elements into a short amount of time (about a year). Of course, since they and many of the supporting characters were real people, we had to return them to their course in history at the end. But it's what makes historical fantasy fun, weaving in the fantastic among real historical events. All our villains are fiction, hiding in the shadows of history and getting in the way of our heroes destinies.
It was an interesting time, the Victorian ideals that rigidly governed their lives were crumbling as the modern world broke through. The British Empire was about collapse, being too big to rule. All those foreign cultures England was trying to reform were also reforming them. How was the bland, proper life English life going to stand up against spicy Indian food and the sexul freedom of the Kama Sutra?