Stefan Salvatore was one of the two main male protagonists of The Vampire Diaries. Stefan was a 171-year-old cured vampire and the distant descendant and doppelgänger of Silas. Stefan was born and raised in the supernatural town of Mystic Falls, Virginia and came of age during the time of the Civil War. Stefan was the youngest child of Giuseppe Salvatore and Lillian Salvatore. He had an older brother, Damon Salvatore, who is also a cured vampire and whom he shared a strained relationship with, stemming from the appearance of Katherine Pierce in which they fought over whilst human.
During the years following his transition, despite the help from close friend Lexi Branson, Stefan has constantly battled with his bloodlust, and during the 1900's after "falling off the wagon" due to Damon's unhealthy influence, he widely became known as the Ripper of Monterey due to his inability to control his blood thirst. For a brief time, Stefan was romantically involved with the Original, Rebekah Mikaelson, and shared a close friendship with her brother, Niklaus.
After many years away, Stefan returned to his hometown of Mystic Falls to visit his distant nephew, Zach. Stefan then saw Elena Gilbert for the first time while rescuing her after her parents' car drove off Wickery Bridge. After finding her personal records and observing her from afar, Stefan determined that Elena was definitely not Katherine. Still, he was strongly intrigued by her and decided to pose as a new transfer student at Mystic Falls High School to get to know her. They were instantly drawn to each other and they immediately bond, beginning a romantic relationship shortly afterwards. However, despite them becoming romantically involved, various and numerous obstacles begin to come between the two, making Stefan and Elena struggle and fight to be together. They grow distance after Elena's transition, and later break up, due to Elena's heightened feelings for Damon. He later discovered that this is due to the creation of a sire bond between Elena and Damon after Elena's transition to a vampire. He then embarked on a journey to Nova Scotia with Elena, Shane, Damon, Bonnie, Jeremy, and Rebekah to seek the the cure that can help break the sire bond.
At the end of the fourth season, Stefan ends up heartbroken when the sire bond is broken and Elena still decided to choose Damon over him. Stefan decides to leave town and start over elsewhere. However, Stefan ends up being confronted by Silas, finally revealing his true form and locks him in a safe underwater.
Throughout the fifth season, Stefan loses his memories due to Qetsiyah's attempt at incapacitating Silas and suffering effects due to Silas' confrontation, he slowly finds closure with Katherine as she helps him overcome his demons. Being a doppelgänger, Stefan's blood is used for a spell by The Travelers in order to resurrect their leader, Markos. During this time, he begins to grow close to Elena again and they are able to form a close friendship. As things begin to spiral out of control, Stefan was unexpectedly killed by Julian, a Traveler warlock, while trying to protect Caroline, but he was resurrected after Damon, Caroline and Elena's plan to bring him back from The Other Side is a success. However after Damon fails to return, he is left devastated at the loss of his brother as the Other Side collapses. Following this, Stefan moved away from Mystic Falls and had tried to start over and move on from the loss, pain and tragedy. Unfortunately for Stefan, he ended up being dragged back to Mystic Falls due to unexpected drama.
During the eighth season, Stefan worked for Cade, the Devil. To keep both him and Damon out of Hell, he fliped his humanity switch off. While a ripper again, he attempted to murder Elena in her coffin, ripping out Enzo's heart, killing him as he was in his way. He then attacks Bonnie before going after Elena, only for Bonnie to use the Cure, taken from Elena's blood, on Stefan in revenge and self-defense. Stefan faints from being cured of his vampirism.
Stefan's life has been fraught with constant change and various complications: from falling in love and being with Elena to mending his complicated relationship with Damon; from sacrificing his freedom for his brother's life to growing apart from Elena after her transition to a vampire, and suffering the guilt that came from making a split-second decision that resulted in Elena becoming a vampire.
He is best friends with Lexi Branson until her death (now reunited in death), and eventually became best friends and married to Caroline Forbes. He was also close friends with Bonnie Bennett and his ex-girlfriend, Elena Gilbert.
Throughout the series, outside forces threaten those he loved and what he most desired: a normal, human life.
Stefan was a member of the Salvatore Family.
Stefan met Valerie and Julian in 1863, at the County Fair in Mystic Falls. Unknown to stefan -who was still human at the time - Valerie and Julian was a Siphoner Witch and a Vampire, who per his mother orders, came to Mystic Falls to make sure Stefan was doing well before they left for Europe. Valerie introduced herself to Stefan, despite Lily's instructions to simply observe him and not interact with him, and the two quickly became smitten with each other. Julian attempted to separate them early on, but Valerie used her magical amulet to cast a cloaking spell so they wouldn't be seen. Stefan ultimately lost his virginity to Valerie that night, though he was not aware that they had conceived a child during their lovemaking. Julian eventually caught them afterward and forced Valerie to leave with him, but before she left, she assured Stefan that she would find her way back to him. At the end of the summer that year, Valerie sent Stefan a telegram asking him to run away with her - Stefan then arrived at their meeting place two hours early with a bouquet of flowers and waited for her there, only to be devastated when she didn't show up. Stefan didn't know that Julian caught her trying to leave and then beat her, causing her to miscarriage - Stefan would only learn the truth about it a 150 years later.