This show is about 2 vampire brothers named Stefan Salvatore and Damon Salvatore both fell in love with one girl because she looked like Katherine and because of her personality was different than Katherine's personality. Katherine was a manipulative, selfish vampire and only cared about herself and not others. In 1864 was when Katherine met the Salvatore brothers, once the Salvatores saw her they automatically fell in love with her. Even though Katherine only loved Stefan, more than Damon. Katherine always compelled the Salvatore brothers into drinking her blood so when they die they come back to life and are in transition of being a vampire. You can choose if you want to feed on human blood or just die, there's no other choice than that. Katherine and her friends came to their town and lived there for a bit. The humans in that town started noticing strange deaths because of bite marks and bodies drained of blood. Katherine had a witch assistant called Emily, she helped humans even though she was best friends with Katherine because Emily knew that her family was also in danger because of her. Emily helped the humans create a vampire compass which leads it to vampires or shows if any vampire is near you.
One day Damon saw Elena (Katherines doppleganger) and talked about her life about what she wanted . Damon then compelled her to forget what he said and to get what you want in life. Stefan one day saw get into a car crash with her mom and dad in it. Stefan tried Saving her father but he said to save Elena instead once he saw her immediately wanted to get to know her.