Imperium Vampirus is an empire ruled by vampires and the main capital for vampires. It was once Transylvania, a historical region where humans once enjoyed the scenery and the historic landmarks like Bran Castle and Corvin Castle, but ever since humans have uninentionally introduced vampires to real life, vampires had taken over Transylvania and humans had evacuate Transylvania permanently. Today, Bran Castle and Corvin Castle still exist, but are now owned by vampires, who had completely taken over all parts of Transylvania, they had renamed Transylvania to Imperium Vampirus, which was now a capital city for vampires.
However, humans and other sapient species retreated underground, in the sewers, in order to prevent further bloodsucking incidents, and formed the Transylvanian Liberation Army.
Transylvania was once home to and visited by humans from 1400s to 2006. Transylvania was a birthplace for various versions of Count Dracula (former fictional vampires). Transylvania was also famous for having famous landmarks such as Bran Castle and Corvin Castle, although they still exist. However in June 19th, 2006, vampires were brought from many films, live action series, anime, etc, ranging from ones that appeared from 1920s films, series, etc to 2017 films, series, etc, thus all vampires have conquered Transylvania, so humans had evacuated the site. Humans were sad and terrified of Transylvania being taken over by the now-real vampires. Eventually, after a successful takeover, the vampires had renamed Transylvania into Imperium Vampirus. They had replaced all buildings that aren't Bran Castle nor Corvin Castle by Gothic castles, with every furniture that humans liked that vampires didn't use (like beds, lightbulbs, etc) by vampire coffins, Gothic candles, and among others that vampires prefered. Imperium Vampirus is now a hostile place for humans, dylanusids, and other sapient species that aren't vampires, while in the underground (mainly in the sewers of the Imperium Vampirus), the Romannian government formed the Translyvanian Liberatiion Army (TLA) to fight evil vampires that govern Transylvania under the government of the Imperium Vampirus.