For example would people in Victorian England call it Victorian London? Would it be a common way of refering to it or would it just be something written down in books?
As with any question, the answer will be different depending on the period and respective title. But it's definitely not unheard of for us to still use the same title for a period as those in the period itself. As one example, we call the 20s the Jazz Age, a phrase used as early as 1922 in the title of F. Scott Fitzgerald's short story collection Tales of the Jazz Age.