Marcus Korolus was born in Rome in the year 136. After he was poisoned by a rival and suffered his first death becoming Immortal, he was mentored by Gaius Septimus. Marcus made his living as an actor, and later mentored Walter Graham.

In the 1620s, Korolus was accused of witchcraft, and was burned alive. The fact that the woman he loved, Lenora, had betrayed him to such a fate, was too much for him, and Korolus went mad. In revenge, he murdered Lenora, taking her scalp. Her death alone didn't satisfy him, however, and he continued to kill other women who resembled her in the same way. His targets were always women who reminded Korolus of Lenora, and had long blonde hair like she had.