Stefan's malevolent vampire brother. He is mostly thought of as selfish and manipulative, but later on begins to display a more caring side. Though his love for Elena is initially one-sided, she begins to develop feelings for him as they work together to save Stefan after he's given in to his Ripper side. They begin dating in season 4, and continue to date (with some breakups along the way) until Elena is put into her deep sleep at the end of season 6. Damon becomes extremely close with Stefan, but also has a close friendship with Bonnie, despite the fact that they hated each other for the first 5 seasons of the series. Throughout seasons 6 and 7, their relationship has developed into a deeper bond, with Damon later confirming Bonnie is his best friend.
In the 1950s, Damon was captured and tortured by the Augustine society, led by the Whitmore family, who experimented on vampires for a "bigger purpose". During his five years of captivity, he meets another prisoner, Enzo, with whom he became best friends with. Eventually, the plan the two made failed at a critical moment and thinking Enzo "died" because of him, Damon turned off his humanity to suppress the guilt and sadness. He sought revenge, an act of hunting down every member over generations that left one alive to carry on the family name until he finally killed the last descendant in the Whitmore family, which ended with Aaron Whitmore's death. Damon's sole purpose in coming back to Mystic Falls was to free his sire Katherine Pierce from a tomb she was never in. Damon deeply loved her after 145 years. After realizing that Katherine never loved him, his love for her fades as his friendship and love for Elena, Katherine's descendant and doppelgänger, grows. Due to her impact on him and the strengthening relationship with his brother, they begin working together to protect Elena, along with her friends and family. He lives with his brother Stefan, girlfriend Elena (when she wasn't away at college), and her brother Jeremy Gilbert (after Elena burned their house down) in the Salvatore Boarding House.