Katherine Pierce (born Katerina Petrova) is a vampire and former lover of Damon and Stefan Salvatore. She is first shown in recurring flashbacks, depicting her physically romantic relationship with the Salvatore brothers, eventually turning them, but was captured by the townspeople of Mystic Falls to be destroyed.
However, behind her sweet nature, Katherine revealed her deceptive side and escaped her would-be death with the help of George Lockwood. 145 years later, Katherine returned to Mystic Falls and started toying with the Salvatores again, 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 curse of the Sun and the Moon.
Katherine is exposed as a doppelgänger who spent her immortal life running from an Original vampire named Klaus, and 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 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.
It was later learned that Katherine wanted all of the vampires that were in the tomb dead, so they would not try to kill her for betraying them to save her own life, and so that Klaus couldn't find out from them that she was still alive. So she sent Isobel to retrieve the invention which is harmful against vampires. She also gave Isobel a lapis lazuli medallion, thus enabling her to walk in the sun. At some point on Founder's Day, Katherine returned to Mystic Falls, Katherine stabs John Gilbert.pretending Katherine kisses Damon.to be Elena. John Gilbert had set off the device and incapacitated the tomb vampires, including the Salvatore brothers. She posed as Elena and fooled many by her deception. Katherine pretended to be Elena and kissed Damon passionately. Jenna, Elena's aunt, interrupted them and unknowingly invited Katherine into the house. She then spoke to John, who told her why he despised vampires so much, believing her to be Elena. Moments into the conversation, she then took a knife and chopped off his fingers, along with his ring and stabbed him. Elena arrived not too long after and heard the noise. She went into the kitchen, curious as to what happened.
John Gilbert being seriously injured, Elena calls for help and is terrified by Katherine's super-speed around the house before leaving. She wreaked havoc for Damon and Stefan, confusing them of who she really loved. Also, she threatened Bonnie, claiming that it never ended well for Bennett witches, but Bonnie used her powers on Katherine, like she did earlier on Damon. Katherine "acted" like she was in pain, but because she was very old she had a certain resistance to supernatural phenomena. She admitted to Stefan that she returned for him, but she was furious because he told her that he hated her. She was furious at the fact of Stefan picking Elena over her. Enraged, she stabs him with a metal rod. Damon demanded the truth after he and Katherine kissed heavily, and she confessed that she never loved him and that it "will always be Stefan" that she loved. Later, she went to see Caroline Forbes and told her to give the Salvatores a message: "Game on." She killed Caroline by smothering her with a pillow, while knowing full well she still had Damon's blood in her system and would come back as a vampire. Katherine next to CarolineKatherine appeard to Caroline as she was waking up, as Katherine gained access to Caroline's house after Caroline's mother mistook her for Elena and invited her in.
Katherine told Caroline to not be frightened, and that they were going to have so much fun together. Katherine revealed some shocking secrets to Stefan, as she made him dream that he was at the 1864 Founder's Ball with her. While there, he noticed that Damon had found someone to entertain himself with. It was shown for that person Damon had in his arms was Elena. Stefan saw, in his dream, that Damon and Elena were on a date and were kissing. Later on after the dream ended, Stefan thought he was holding Elena in his arms, but then realized it was Katherine. Later on, the two talked and Katherine proved that she never compelled Stefan to love her, his love for her being real, and she only compelled him to cover up his fear of vampires.
Also, it was revealed that Katherine escaped the tomb with the help of a werewolf, George Lockwood, to whom after she got out, Katherine gave the Moonstone. In 1864, she also betrayed her best friend Pearl and all the other tomb vampires just to fake her own death. However, she was in love with Stefan, and genuinely cared about him. After the interrogation, she finally met her doppelgänger, Elena. The Salvatores try to kill Katherine.It was soon revealed that she was sleeping with Mason Lockwood, whom she had been using to find the moonstone to hand over to Klaus to be free from him and to break The Sun and Moon curse. But she needed a werewolf to do so. After Mason was killed, Katherine had compelled Matt to pick a fight with Tyler, so that Tyler would kill him and trigger the curse, because Katherine needed a new werewolf to replace Mason. Damon imprisons Katherine.Katherine decided to retrieve the moonstone herself with the help of Lucy, a witch, who is Bonnie's cousin. She danced with Stefan but when he refused to hand over the stone, she killed Aimee Bradley. Caroline successfully lured Katherine into a room upstairs that Bonnie had put a spell on so vampires couldn't get out. In the attempt to kill her, Damon and Stefan partook in an intense fight between the three of them. Lucy, however, had cast a spell over Katherine and Elena so whatever happened to Katherine would happen to Elena. However, Lucy turned the tables on her and worked with Bonnie, using a spell that incapacitated her. When she woke up, she was imprisoned in the tomb where Damon said she should have been for a long time. As Damon closed the door of the now sealed tomb, Katherine screamed that Elena was in danger and needed to be protected. It was later revealed that Katherine did have a child before she was turned.
Elena visited her and they had a conversation about her past, as Elena constantly gave her blood from a bottle to give her enough strength to talk. She told Elena that she was the first Petrova doppelganger, which means she needed to be sacrificed to break the curse but she escaped A severely weakened Katherine greets Elena.Klaus and became a vampire, becoming useless for the sacrifice. Klaus wanted to break the curse so vampires could walk in the sun, and since Elena looked like Katherine, it meant Elena was the second Petrova doppelganger and she was human, which Katherine said would mean Klaus would be coming after her to break the curse. When Klaus came after her, she was given blood by Rose to heal so she wouldn't die, and she later hung herself to be free. When Stefan finally found Elena, Katherine informed them that Klaus would kill all the people Elena loved, Katherine tearingjust like Klaus did to her. Stefan accused her of tricking Elena, to get herself out of the tomb but Katherine told Stefan that she wanted to be in the tomb due to her protection from Klaus. Katherine later read a Petrova history book with a drawing of her family with tears in her eyes, showing she had not completely lost her humanity. Bonnie burned the picture of Katherine that belonged to her in 1864 so that Stefan could put it on her, rendering her unconscious for 1-3 minutes. Jeremy ventured into the tomb and asked Katherine for the moonstone, and he threw wood into her chest so he could spray the dust on her. While she was unconscious he went in and obtained the stone, but she awakened and attacked him. Stefan was forced to go into the tomb to save Jeremy and was now stuck in there with Katherine. Katherine was very pleased with herself; she and Stefan talked in their few hours in the tomb, which proved that Katherine loved him even if she was hard on admitting it. Damon and KatherineAfter Elena's deal with Elijah, the warlock Jonas broke the spell of the tomb, allowing vampires to come out. Katherine, though, was compelled by Elijah to stay inside. Katherine begged Damon not to kill Elijah, because then she would be stuck in there forever.
However this was later revealed to be a lie, as she knew that killing the Original that compelled her would actually have the opposite effect and she would be free to leave the tomb. Katherine left the tomb and bathed in Damon's shower, asking him if he had a robe when he walked in on her. She further surprised Damon by restating her pledge to help him protect Elena. Katherine subsequently takes up residence with the Salvatore brothers (though their willingness to allow her to stay is tentative, at best), much to the displeasure of Elena.
Katherine repeatedly states that she will help them to deal with Klaus, and engages in research with the brothers. She is staked and nearly killed by Luca Martin when he infiltrates the mansion via astral projection in an attempt to release Elijah, but is rescued by Stefan and Damon, who unwittingly burn Luca to death. As his father strikes out in a rage against Elena, Katherine tricks him into believing that she is her doppelganger and murders him to protect everyone. She also repeatedly flirts with Damon, despite admitting to him that she knew that the dagger would kill the vampire who used it, and, having to make a choice between himself and Stefan, she chose Stefan once more. She tried to evade Klaus with the help of Isobel, but was double-crossed and given into Klaus's custody.
In Tha Last Dance, Klaus/Alaric compels her to tell him everything she knows and stuff she wouldn't know, he denied her request to be killed because it was an act of "kindness" to kill her so soon after he searched for her for over 500 years and tells her that her death is going to last at least half that long. After their conversation Klaus/Alaric pulls out a pocket knife and compels her to stab herself until he returns from laying eyes on his "precious" doppelganger. In Klaus(episode), Katherine asks Klaus/Alaric why would he undo the curse in Mystic Falls knowing that a lot people will try to stop him. Klaus/Alaric reveals to her that Katherine dances.he can only undo the curse because it's the doppelganger birthplace. Katherine then replies that she didn’t know that was a requirement. Klaus/Alaric replies to her saying "how could she have known because she betrayed him and fled England before he could give her the details but he did find her birthplace and slaughtered her family, so their cool".
As Klaus/Alaric is leaving he tells her she can't leave until he tells her to. Later Damon and Andie Star go to Alaric’s apartment to discover Katherine is alive. Damon tells Katherine he has vervain, which won’t undo Klaus/Alaric’s compulsion but it will stop further compulsions. But before he gives it to her, he wants to know why she double-crossed them with Isobel. She didn't think the others could stand a chance against Klaus and she was looking out for herself. Damon gives her the vervain and tells her she owes him and he will collect. Later that night Katherine was drinking and dancing until Klaus/Alaric returns to the apartment in a bad mood and tells her Alaric's body is no longer useful. Then Katherine asked Klaus/Alaric if he wanted a drink but he declines, Katherine insists that he should have drink. Klaus/Alaric snatches the bottle away from her, throws it against the wall and "compels" her to sit down and shut up. When Maddox returns with Greta and his casket, she looked at the casket knowing she was about to come face-to-face with the vampire she fears the most. After Maddox and Greta are done taking Klaus out of Alaric's body, the casket is opened and she begins to show fear as the real Klaus walks out. Katherine shock after Damon states he been bitten by a werewolfIn The Last Day, Damon goes to Alaric's apartment to collect his debt for giving her vervain. He asks Katherine where Klaus is keeping the werewolf. Katherine is reluctant to help out but reveals that Klaus has captured Caroline and Tyler. She is shocked to learn that Elena has vampire blood in her system and Damon warns her that she would have to compete for Stefan's love with Elena forever. Katherine reveals that Caroline and Tyler are being held in the tomb. Klaus returns to Alaric's apartment and is immediately suspicious of Katherine. He compels her to tell him what she has been doing but, as she is taking vervain, she is able to lie. He is still suspicious and 'compels' her to take off her bracelet, walk to the window and stand in the sunlight. Katherine has to do it and screams. Eventually Klaus believes she is compelled and says she needs to do something for him. Later that night Klaus returns to Alaric's apartment and tells Katherine that Elena is with Greta, Damon appears and tells Klaus he has to postpone the ritual, explaining that he rescued the werewolf and vampire and killed Maddox. Klaus then tells Katherine to leave the room so he and Damon can talk. After Klaus knockouts Damon, Katherine wakes him up and tells him that Klaus has gone to begin the ritual. She admits that she had to do something so Klaus wouldn't realize she was on vervain, and reveals that Klaus made her call to lure someone, explaining that he needed another vampire.
Damon asks why Klaus didn't use him as the vampire. Katherine admits that Klaus couldn't because Damon was as good as dead. She suddenly notices a mark on Damon's arm and asks what it is and he replies "werewolf bite." In The Sun Also Rises, Damon shows Katherine his werewolf bite but decides to leave. She is hurt that after 145 years he is leaving without saying goodbye and tells him not to depart on bad terms. She insists that she didn't have a choice and had to lure Jenna for Klaus, adding that she chose her life over Jenna's. Damon points out that Katherine will survive this without a scratch. Katherine points out that she doesn't let love get in the way and Damon tells her to enjoy an eternity alone. He leaves to offer himself to Klaus, but Katherine insists that Klaus won't accept him as his blood is impure. In As I Lay Dying, Damon has a flashback and remembers speaking to Katherine in the 1860s. She asks if he will miss her while he is off fighting and he says he will, but points out that she will still have Stefan.
Katherine asks if it is so wrong for her to want them both. However, Damon hallucinates that Elena has joined them. Elena tells him that Katherine after being bittenKatherine was just toying with him and he could have walked away - he had a choice. Klaus says that's the kind of vampire he could make a deal with. He calls Katherine over and bites her, shocking her as she realizes she now has a werewolf bite. He then feeds her his blood and she heals so that Stefan realizes that Klaus' blood is the cure. Meanwhile, Damon arrives at the screening and hallucinates, thinking he is seeing Katherine.
Elena runs through the screening looking for Damon. She finds him and drags him away, but as she does Damon gets confused, mixing the present with the past, thinking he is chasing Katherine through some woods. He remembers begging Katherine to feed him her blood so they could be together forever. Back in the present, he tries to bite Elena as she begs him to stop, explaining that he is hurting her. Klaus calls over Katherine and compels her to take his blood to Damon and come right back - but she is still on vervain. Katherine rushes off as Stefan worries that she will never deliver the cure to Damon.
Katherine appears and says he should be thanking her as she brought the cure. She says she decided to deliver it because she owed Damon. Elena asks about Stefan, but Katherine asks if she really Katherine and Elenacares. Eventually, she reveals that Stefan is paying for the cure. She explains that he gave himself over to Klaus and sacrificed everything - including Elena - to save Damon. However, she tells Elena that at least she will have Damon to keep her company. "It's OK to love them both," she adds. "I did." She throws the cure at Elena and walks away. When Stefan confirms that Katherine got to Damon in time he tells Klaus that she escaped, but Klaus reveals that he knew she was on vervain and that she won't get far.
Katherine in ChicagoKatherine made her first appearance in the season in The End of the Affair where she calls Damon and gives him information on Stefan's whereabouts. She is later shown to be in Chicago. In 'Disturbing Behavior, Katherine is shown to still be in Chicago, there to try and help Stefan, but he declines her invitation and doesn't take her warnings to mind. She later saves him from Gloria's torture by stabbing her in the neck, and asks to be a part of Stefan's plans, where he yet again refuses her. Towards the end of the episode, Katherine fooled Bonnie, and manages to steal Esther's Talisman, Katherine with the Original Witch's Talisman Necklaceshowing up at Damon's house seconds later with the pendant, proposing they should team up and get away from Mystic Falls and go on a little "road trip". At a rest stop, she reveals to Damon that she has kidnapped Jeremy. She needs the help of Jeremy to contact Anna because he is able to communicate with ghosts and she is the only one who knows anything about Mikael, a vampire who hunts vampires and the only one who can kill Klaus for good, who is now locked in a tomb by a witch since the 1990s. Anna reluctantly gives them information about him, stating that Mikael will kill all of them if awakened. Katherine ignores her warning, and is able to locate his tomb with Jeremy's help. Katherine spent two days unsuccessfully trying to get Mikael to feed, and finally brings him a human, which he refuses and pleads for her to remove the blood-dripping body from him. As he continues to grumpily lie in his coffin, barely awake, she begins to doubt all of his power, and asks whether he can kill Klaus or not, which Mikael confirms, stating that he has denied himself human blood, and proceeds to feed on Katherine when she removed his bindings; her status remains unknown. Katherine as Elena getting stabbed by Mikael.In Homecoming, Damon enlists Katherine in a plan to kill Klaus. She pretends to be Elena so that Elena wouldn't be killed if Mikael used her to bait Klaus. However, during the party, Klaus, thinking that she was Elena, revealed that in the event that Klaus is killed, the other Hybrids will kill Damon. Katherine then runs back to the Salvatore house and tells Stefan this. She tries to convince him to care enough to stop Damon from killing Klaus, because she is going back to see the plan through. She then returns to the party. Mikael uses the fact that the hybrids are part vampire to compel one of them to grab her, threatening to kill her if Klaus does not leave the Lockwood house. Klaus, believing that he is bluff KABOOMing, says go ahead. Mikael then stabs Katherine right as Damon jumps Klaus. Much to the shock of Klaus and Mikael, Katherine stands up, and throws wolfsbane (and possibly vervain) grenades at the approaching hybrids. After Stefan stopped Damon, he and she left Mystic Falls. She calls Damon and says that it was a really well thought out plans, and her regret that it didn't work out the way everyone hoped. Stefan asks why Katherine, who wanted Klaus dead for 500 years, would stop a plan to kill him just to save Damon. Katherine then states that humanity is the greatest weakness of the vampires, and no matter how hard one tries to shove it down, it fights back, and sometimes she lets it. She states that, despite everyone thinking that she only cares for herself, she does love Stefan and Damon too, Stefan states that he doesn't want his humanity after everything he has done. Katherine says that he has to, because she needs him to feel, specifically, feel angry at Klaus for everything he has done. She convinces him to steal the coffins that the originals were kept in, greatly angering Klaus, then 'puts about a million miles between her and Klaus.'