Alexander of Brennenburg is the main antagonist of the video-game, Amnesia: The Dark Descent.
Alexander was a being who has been masquerading as a succession of Prussian barons during his centuries-long life. Alexander was a being from another world who was exiled to Earth for unknown reasons. He was forced to take the form of a human and built Castle Brennenburg in Prussia. He built the Inner Sanctum beneath the castle to create a portal which h ould us to return to his world. Alexander gathered as many of the Orbs as he could find in hopes of opening the portal to return to his original homeworld. He tortured captured victims to extract a mystical "vitae" from them, with which to perform mystical rituals in order to achieve this goal. Years later, he came into contact with Agrippa where they studied the Orbs together, but Alexander betrayed Agrippa and imprisoned him in a motionless body. Years later, Alexander contacted Daniel, who had recovered an Orb from Algeria and returned to England with it. He manipulated Daniel into helping him with his horrific experiments, promising him protection from the Shadow in return. Alexander manipulated Daniel into kidnapping people and imprisoning them in the Inner Sanctum for his rituals. However, as soon as Daniel's work was complete, Alexander sealed himself in his Inner Sanctum and abandoned Daniel, who drank an amnesia drink and vowed to kill Alexander for his sins. Alexander began to finish his work on the portal and sent his monstrous minions, the Gatherers to kill Daniel to prevent him from interfering with his plans and they roamed the castle searching for him. The Gatherers finally captured Daniel heading for the Inner Sanctum and imprisoned him here Alexander taunted him in his mind that Daniel is blaming him for the crimes Daniel did himself for Alexander and that he would never pay off his sins. Daniel escaped the prison and gained access to the Inner Sanctum just as Alexander prepared to activate the portal.