Petronia is the maker of Manfred Blackwood and his descendant, the popular Quinn Blackwood. Petronia is also the only known hermaphrodite vampire. She appears in Blackwood Farm (2002).
Petronia is born decades before the Common Era, in Rome, during the reign of Julius Caesar. Her mother is an actress, and her father is a gladiator. Born a hermaphrodite, she is prostituted by her parents, until she is able to carry a sword and shield and be trained as a gladiator. By the age of fourteen, she is a fierce and murderous spectacle in the gladiators’ arena. She continues to fight and win, with her parents charging higher and higher fees for spectators to behold Petronia’s peerless strength and ability. While she is still a girl, her parents sell her for a great fortune to a master who treats her cruelly, chaining her to her bed every night and during the day sending her into arenas to fight vicious animals. Her indomitable will does not allow her to be defeated against lions or tigers. She slays them all, and the paying crowd loves her.
During all that time, one customer continues coming back to pay to see her fight and to pay to be with her intimately. It is the vampire Arion. One night, when he can no longer bear to see her enslaved to such a merciless master, he buys her freedom and gives her a purse filled with money, telling her to go wherever she desires and do whatever she wants. But she does not know where to go or what to do, except to follow after Arion and love him.
Petronia makes a home with Arion in first-century Pompeii, where they set up a shop and he teaches her how to make and sell cameos. They continue this peaceful lifestyle until Mount Vesuvius erupts and destroys Pompeii. Arion stays in the Bay of Naples while Petronia saves the shop’s slaves and wares. In response to her bravery, and for his love for her, Arion turns Petronia into a vampire and teaches her how to kill only evildoers, how to hide their bodies, and how to survive the long years of immortality.
Petronia moves with Arion to Naples, where they sell diamonds for centuries. During the late nineteenth century, Petronia meets Manfred Blackwood, who has recently traveled to Naples. She is fascinated by his accounts of Louisiana’s swamplands and travels to the port of New Orleans to visit. She adores Manfred’s island, which he calls Sugar Devil Island, because she can easily hunt victims and hide their bodies. Manfred makes her a tomb so she can sleep during the day. One night, she and Manfred make a deal: he will give her the island on the condition that she will make him a vampire. Petronia readily agrees to this, and even helps Manfred brutally murder his second wife, Rebecca. After Petronia receives Sugar Devil Island, she returns to Naples, but Manfred follows and demands that she keep her end of the bargain. At first she balks, but Arion commands her to keep her word, so Petronia turns Manfred Blackwood into a vampire.
They make a small coven and live together for many years. Relocating finally to Sugar Devil Island, Petronia and her coven members watch the Blackwood family mature into the twentieth century, with the birth of Tarquin “Quinn” Blackwood. Petronia has a special interest in Quinn. She visits him and Aunt Queen on Blackwood Farm, intrigued to know him more intimately. When his romance with Mona Mayfair intensifies, Petronia kidnaps him and turns him into a vampire. Along with Arion and Manfred, she teaches Quinn how to hunt evildoers, hide their remains, and keep the existence of vampires away from suspicious mortals.
Petronia soon learns that her fledgling Quinn is being haunted by the ghost of his mortal twin brother, Garwain. Motivated by a great desire to help him, Petronia introduces Quinn to the Vampire Chronicles, in the hope that the vampire Lestat might have some way of helping her fledgling.
For more perspectives on Petronia in the Vampire Chronicles, read the Alphabettery entries Arion, Garwain Blackwood, Goblin, Manfred Blackwood, Quinn Blackwood, Rebecca Stanford, and Sugar Devil Island.