|“||We manipulate, we thirst for power, we control, we punish, but our actions are driven by one singular place deep inside: We're alone... and we hate it.||”|
The two first met in the 1490's, after Katherine had been exiled to England from Bulgaria. Rebekah was living as a noblewoman in England, along with her brothers Elijah and Klaus, when she and her family were introduced to Katerina Petrova, as she was called at the time. Elijah and Klaus quickly realized that Katerina was the Petrova doppelgänger they had been waiting for for almost five hundred years, and planned to sacrifice her in order to break the curse binding Klaus' werewolf heritage. After Katerina found out she had to die, she escaped with the help of several of the Mikaelsons' associates, Trevor and Rose. This act destroyed Klaus and Elijah's bond as brothers for centuries, and Rebekah subsequently held a grudge against Katherine ever since.
Rebekah was living with Klaus in Chicago after they had fled their home in New Orleans when Mikael tracked them down. It was in Chicago that the siblings met Stefan Salvatore, who became close friends with Klaus and began a romantic relationship with Rebekah. Katherine, who was also in the city at the time, likely to check up on Stefan, observed him and Rebekah from afar. After a police raid led by the then-police chief Mikael cleared out the speakeasy, Katherine spotted Rebekah's necklace on the ground. She moved to pick it up, but when she saw Stefan approaching where she was standing, she ran away before Stefan could see her.
Throughout The Vampire Diaries Series
In Stand By Me, Damon informed Rebekah that Katherine had stolen the Cure from right under their noses after feeding Jeremy to Silas to wake him. Damon and Rebekah ultimately teamed up to find her, and ended up capturing Galen Vaughn to get information about Katherine and her plans.
In Bring It On, it was revealed that Katherine had found Hayley in New Orleans at some point prior to the Mystic Falls Gang's trip to the island, and Katherine told Hayley that she could help her find information on her real parents if Hayley gave her information on the cure and the gang's plans to retrieve it. Katherine then sent the vampire Will to kill Hayley, as she became a "loose end" after she had served her purpose to her. Klaus however, bit Will and saved Hayley from being killed. After Rebekah and Damon found Will afterward, severely out of it from the hallucinatory and hunger-inducing effects of a hybrid bite, and Damon killed him before he could tell them anything about the cure or Katherine. Damon insisted that it was to save Will the pain of dying from his bite, but Rebekah reminded him that she had a vial of Klaus' blood to heal him, and correctly guessed that Damon killed him so he couldn't give Rebekah the information about Katherine's whereabouts, as she knew Damon wanted the cure for Elena instead.
In Because the Night, Damon took Elena to New York City under the guise of getting away from Mystic Falls while she adjusted to having her humanity switch turned off, but in reality, he was planning on figuring out where Katherine (and by extension, the cure) were hiding by searching through Will's notes. However, Rebekah followed them up to New York, where the girls decided to team-up, as Elena didn't want the cure, and she figured that finding Katherine and getting the cure for Rebekah would ensure that the Salvatore brothers wouldn't use it her.
In American Gothic, Elena and Rebekah tracked Katherine down in Pennsylvania and forced her to give them the cure. Elena then posed as Katherine to meet with Elijah while Katherine and Rebekah stayed at the café. Katherine sarcastically remarked that she had forgotten how charming Rebekah was, and Rebekah replied, "I'm surprised you remember me at all, seeing as though you were so busy wedging yourself between my brothers." Later, Katherine revealed to Rebekah, Stefan and Damon that Elena was with Elijah, and slyly confessed that she and Elijah were lovers. She then took Damon and Rebekah to her house under the guise of handing over the cure to them. However, she tricked Damon into putting his arm into a fish tank full of vervain before dunking his head into the water and trying to run out of the house with "the cure." Rebekah ended up blocking her way and insisted that she either give her the cure or she will be killed. Katherine, not wanting to die, threw "the cure" into the air to distract her before running away. Rebekah grabs "the cure" and broke it open to drink it, despite Damon and Stefan's protests. She passed out from the contents, but when she awoke, she realized that she was still a vampire, and Stefan guessed that Katherine had made a fake "cure" out of an extra-concentrated dose of vervain. In The Originals, Katherine, who was waiting for Elijah to return from New Orleans, was lurking at Rebekah's home while Rebekah talked to Elijah on the phone. When Rebekah noticed her, she retorted that she'd give Katherine a play-by-play if she didn't have the air of someone who had been lurking and listening. Katherine insisted that Elijah wouldn't come back until he convinced Klaus to do the right thing. Rebekah, clearly annoyed by Katherine, argued that she didn't know her brothers half as well as she did. Katherine says that she's wrong and that Klaus won't
Still, Katherine maintained that Rebekah was wrong, and explained that Klaus wouldn't be able to walk away from what he had learned in New Orleans, because deep inside, she and Klaus were the same person who was ultimately driven by one place deep inside. Wen Rebekah then asked her what it was, Katherine replied, "We're alone, and we hate it." She then told Rebekah to let her know when Elijah came home, and that she would wait for him. Later, when Elijah returned from New Orleans, he and Rebekah began to argue about whether or not they should follow Klaus to live in Louisiana. Rebekah insisted him that she owed Klaus nothing and that she would stay in Mystic Falls to live her life the way she wanted. When she then suggested that if he was smart, he would do the same, Katherine agreed with Rebekah and reminded him that Klaus was "stark-raving mad and completely irredeemable."
- Katherine (to Elena): "Oh well, it's a beautiful place to die."
- Rebekah (pushes Katherine to the ground): "I couldn't agree more you've chosen a beautiful place to die."
- (Katherine starts to stand up but Rebekah stabs her with a fork in the hand, Katherine moans in pain.)
- Rebekah: "You're not going anywhere."
- Katherine (through her teeth): "I forgot how charming you were."
- Rebekah: "I'm surprised you remember me at all. Seeing as though you were so busy wedging yourself between my brothers."
- Rebekah: "Where's the cure?"
- Katherine (smiles): "I'm sorry, I'm on vervain."
- Rebekah: "Well, I'll just torture it out of you for fun."
- Katherine: "Why do you two want it, anyway?"
- Rebekah: "Question is why you want it? Let me guess, to kill Niklaus?"
- Katherine: "I've spend the last five hundred years running from your big brother. I have no intention of being in a sniffing distance of him. But, since it can be used against him, I'm sure he's just itching to get his hands on it. I give him the cure, he gives me my freedom."
- Rebekah: "You know, its funny-- I've always been a little envious of the legend that is Katherine Pierce. The way you wrap men around your little finger, the way Elijah betrayed Klaus for you, the way the Salvatore brothers stumbled head over heels for you. And yet, here we are, all these years later in a town that you've had to compel into liking you. (She laughs) Oh, I'm sorry, I shouldn't laugh. It's really more sad than funny."
- Katherine: "You know you can't split the cure with Elena, right?"
- Rebekah: "She doesn't want it."
- Katherine: "Oh no? But you do, you wanna take it? Are you really that dumb, or just naturally blonde?"
- Rebekah: "I want a normal life again."
- Katherine: "You mean you want a do-over. Well guess what? You can't have it. The cure will only take away your immortality. Everything else you hate about yourself, you'll still wake up with that in the morning, and you won't even be able to compel yourself a friend."
- Katherine : "You're wrong. Klaus won't be able to walk away from this. He and I are the same. We manipulate, we thirst for power, we control, we punish, but our actions are driven by one singular place deep inside."
- Rebekah "And what's that?"
- Katherine: "We're alone. And we hate it."
- Originally, Katherine implied that she had never actually met Rebekah, telling Stefan she had only heard of her, but in American Gothic, it was confirmed that the two had interacted with one another during their time in England in the 15th century.