Campaigns (or, more properly, “chronicles”) in the World of Darkness involve a lot of different elements. These gamelines have been celebrated for decades as rich storytelling systems that have huge followings but they also are notoriously dense in lore. If you want to start a new campaign using the Chronicles of Darkness, here is a short list of items to get your gaming group up to speed.
Onyx Path, the current publishers of the World of Darkness lines, have been doing a lot lately to come up with material for historical settings. White Wolf did their share with Requiem for Rome, the vampire setting in the Roman Empire, and Mage Noir, a much thinner book about mages in World War II and after. Onyx Path continued with Victorian Lost, a changeling sourcebook for 19th-century England, and then decided to make a sourcebook with just a bunch of different historical settings, a book called Dark Eras that they would Kickstart.
Then things exploded.