Over eight seasons, the supernatural drama The Vampire Diaries created a complex web of cross-linked histories, sire bonds and flashbacks. So much happened -- and so much backstory was given -- that at times it became hard to keep the facts straight. A case in point is the history of when and how the Salvatore brothers turned into vampires.
Let's straighten the jumbled events and explain, once and for all, how Stefan and Damon's lives took a bloodsucking turn.
Meeting Katherine Pierce
At some point in 1864, Katherine Pierce arrived at the Salvatore Estate in Mystic Falls with the witch, Emily Bennett, and met 17-year-old Stefan and 25-year-old Damon for the first time. They were both instantly attracted to her, and eventually, both fell in love with her. Damon even deserted the Confederate Army to hurry back to Katherine after his leave was over, even though she made it evident on many occasions that she preferred the younger Salvatore.
During a passionate night together, Katherine suddenly bit Stefan, revealing she was a vampire. Stefan lost consciousness and woke up the next day afraid of her, so she compelled him to not tell anyone what he had learned and to continue as usual as she had planned "a future, for you, me and Damon."
While it is not revealed how Damon came to know Katherine was a vampire, he willingly drank her blood as he wanted to give up his human life and spend eternity with her.
Damon and Stefan Wake Up As Vampires In Transition
Stefan inadvertently tipped off his father, Giuseppe, about there being vampires in Mystic Falls when trying to dissuade Giuseppe from gearing the town members to hunt and kill vampires. His father then drugged Stefan with vervain. When Katherine tried to feed on his blood that night, the vervain poisoned and weakened her, leading to her capture. And when Stefan and Damon tried to free her, their father shot them dead and recaptured Katherine, seemingly killing her by burning her alive.
As both brothers died with vampire blood in their systems, Stefan and Damon woke up the very next morning, healed and alive. Emily Bennett explained she found them dead in the woods and brought them to a nearby quarry. She revealed that while Damon had been willingly drinking Katherine’s blood, the vampire had been compelling Stefan for weeks to drink her blood and then forget about it. As a result, the Salvatores were transitioning into vampires and could choose to complete the process by feeding on human blood or die instead.
Initially, both brothers chose the latter option as they didn’t want to live forever without Katherine. But when Stefan went to see his father one last time and Giuseppe tried to stake him, Giuseppe was accidentally stabbed by the stake, triggering Stefan’s bloodlust. After that, Stefan couldn’t help but feed on his father, completing his transition and becoming a full vampire.
Damon Completes His Transition
Not wanting to live eternity alone, Stefan compelled a young girl and took her to Damon. He tried to convince Damon to become a vampire of his own free will by telling him how amazing being a vampire felt, how he could turn off his emotions and have heightened senses and speed. When Damon still refused to change his mind, Stefan bit the girl and forced Damon to smell her blood. This suppressed his resolve and Damon fed on her, resulting in his completing his transition as well.
But Stefan’s dream of he and Damon being companions forever was shattered when an incensed Damon promised Stefan that he would give him an eternity of misery, not because Stefan forced him to become a vampire, but because Katherine turned Stefan instead of just Damon.