Katerina Petrova

“Humanity is a vampire's greatest weakness. No matter how easy it is to turn it off, it keeps trying to fight it's way back in. Sometimes I let it.” – Katherine to Stefan (in Homecoming).

Katerina Petrova (Bulgarian: Катерина Петрова; English:Katherine Pierce), is a vampire and the former lover to both the Salvatore brothers, Damon and Stefan. Katerina first appeared in recurring flashbacks, depicting her role and her physically romantic relationship with the Salvatore brothers, eventually turning them both into vampires, but was captured by the townspeople of Mystic Falls to be destroyed. To Klaus' knowledge she is a part of the Petrova Doppelgängers family line.

However, behind her sweet nature Katherine has revealed her deceptive side by escaping her would-be death with the help of George Lockwood in 1864. 145 years later, Katherine returned to Mystic Falls, toying with the Salvatores again and cutting off her loose ends by destroying the tomb vampires. Katherine was deeply hated for the murder and the turning of Caroline Forbes into a vampire and using a werewolf, Mason Lockwood, to retrieve the moonstone, an essential element to break The Sun and the Moon Curse. Katherine is exposed as a doppelgänger who spent her immortal life fleeing from an Original named Klaus.

Although she chose Stefan over Damon, she promised John Gilbert that she would help protect her descendant Elena Gilbert, who is the center of the Salvatore brothers hearts. She is initially portrayed as the main antagonist, but the arrival of Elijah, an Original vampire, diminishes her attitude and frightens her with the knowledge of Klaus, causing her to flee Mystic Falls.

Katerina Petrova is a member of the Petrova Family.