A man of noble birth, Tahd spent much of his life serving causes of goodness and law, most notably as a warrior who endlessly fought against the merciless onslaught of the Lords of Dread. His relentless battle against the Dark Lords took their toll upon him however, and by the time he finally destroyed the Lords of Dread and reached middle age, Tahd came to believe he had squandered his life and his youth. With this dark mood upon him, he came to conquer the region known as Barovia, and assumed lordship there, taking as his residence the pre-existing castle known as Ravenloft. From this position of power and security, he called for members of his family "long unseated from their ancestral thrones" to join him, including a younger brother named Sergei.
Some time after this reunion, the Count himself fell in love with a young Barovian woman, Tatyana, though she accepted his affections at first for quite a long while, she eventually grew distant from him when he began to act differently then he previously did and eventually rejected his affections. Filled with despair and hatred for what he was becoming, Tahd sought magical means to restore his youth. In a moment of desperate frustration, he "made a pact with death - a pact of blood" which also affected Tatyana's unborn child Strahd. Tahd murdered his brother Sergei as a sacrifice for his blood pact and pursued the fearful Tatyana until she escaped Ravenloft and disappeared. Tahd himself was shot down by the arrows of the castle guard when he tried to pursue her. Even so, he did not die, but went on to destroy the lands of Barovia as the Prince of Darkness, the first vampire to exist.Now he wages an endless conquest against Aldrazar to have his revenge on the world, believing mankind to have betrayed him many years ago.