It's known for its romance, supernatural creatures and endless death scenes, but what The Vampire Diaries really did best was a flashback episode. From Ancient Greece to the early noughties, the show relied on throwbacks to explain its complex storylines and characters — to overwhelmingly positive fan response.
Multiple flashback episodes rank amongst the highest-rated of the entire show. While it's always fun to see characters transported to new times and places, the best flashback episodes weaved these timelines together to create one big, overarching, supernatural storyline that transcended beyond just Mystic Falls in the 21st century.
Season 2, Episode 9 — Katerina (8.6)
Even though fans loved Katherine from the very beginning, it wasn't until season two's "Katerina" that they really started to feel sorry for her. Sitting down with Elena in the tomb, Katherine recalls the traumatic events that made her who she is today.
Not only was her daughter taken from her at birth, but Katherine was hunted by Klaus (who needed both her and the moonstone for his sacrifice) and took her own life to save herself, turning her into a vampire. As a punishment, Klaus killed her entire family. It's the most tragic backstory of any character in The Vampire Diaries — and more than explains Katherine's villainous personality.
Season 1, Episode 6 — Lost Girls (8.6)
Not only is this the first flashback episode of The Vampire Diaries, but it also happens to be one of the best. After six episodes of hearing all about Katherine, viewers are transported back to 1864 to learn more about the vampire who broke both Salvatore brothers' hearts.
Nina Dobrev triumphs in portraying Katherine as Elena's devious and manipulative polar opposite, creating one of the show's most beloved characters. This episode is also where season one's drama really kicked into gear, with Katherine's introduction filling in the gaps of Stefan and Damon's rivalry and paving the way for storylines like the tomb vampires.
Season 5, Episode 15 — Gone Girl (8.7)
Years after she was first mentioned, Katherine's daughter Nadia joined the show in season five. Now a vampire — and a member of The Travelers — she's spent five centuries searching for her mother, as chronicled in "Gone Girl."
It's a tearjerker of an episode, with Nadia hallucinating in the wake of a lethal werewolf bite from Tyler. However, the most moving moment comes Katherine herself. Despite her reputation as a cold-hearted villain, she sacrifices herself to see her daughter one last time. Stefan kills her, and she finally gets the dramatic send-off her character deserves.
Season 5, Episode 10 – 500 Years Of Solitude (8.7)
Shows always go all out for their 100th episode, and "500 Years of Solitude" is no exception. As a recently human Katherine nears the end of her life, she remembers her origins in 15th century Bulgaria. From giving birth to her daughter Nadia to Klaus' massacre of her entire family, she flashes through some of her most pivotal moments.
Katherine is one of the show's best villains, so focusing an episode on her demise was always going to get a big reaction. What this episode really does is reinforce the fact that Katherine has always been the ultimate survivor — which makes her hijacking Elena's body to save herself an even more believable twist.
Season 6, Episode 15 — Let Her Go (8.8)
It's rare that a character gets a natural death in The Vampire Diaries — which is exactly what makes Liz Forbes' death from cancer so tragic. In the wake of her passing, Caroline thinks back to her mother looking after her as a child, while other flashbacks also show the aftermath of Damon and Stefan's mother's death.
Death is a constant presence in the show, yet six seasons in it still manages to find new ways to make it hurt. What this episode proves more than anything is that even though these characters might not be mortal anymore, their emotions are still so human. Caroline turning off her emotions is shocking, but relatable to anyone who's experienced a similar loss.
Season 3, Episode 8 – Ordinary People (8.8)
Season three of The Vampire Diaries is all about the Originals, with each episode slowly revealing more about the world's first family of vampires. Rebekah sits down to tell Elena more about her past, and "Ordinary People" drops some of the biggest twists so far — namely the fact Klaus was conceived out of wedlock when his mother had an affair with a werewolf.
For such a twisted, supernatural crew, this episode makes it clear that ultimately the Mikaelsons had problems like any other family. It's also the first time viewers are introduced to the Mikaelson sibling mantra — "always and forever" — which ends up being the core of TVD's spin-off, The Originals.
Season 3, Episode 3 – The End Of The Affair (8.8)
All it took was one episode for Rebekah to cement herself as one of the show's most beloved characters. In her debut, Rebekah is seen in a flashback to the 1920s that explores Stefan's relationship with both her and her brother, Klaus.
The 1920s flapper setting already sets this glamorous entry apart from other flashback episodes in the show, but it also just happens to be packed with solid moments. Viewers get their first proper look at Ripper Stefan and see the two contradictory sides to Rebekah's personality — the deadly Original vampire, and the girl who loves too much. It's no surprise many fans feel Rebekah is a character who left The Vampire Diaries too soon.
Season 2, Episode 19 – Klaus (8.9)
After being teased as the new big-bad of The Vampire Diaries throughout most of season two, Klaus is finally unveiled in this eponymous episode. For the first time, viewers get to see the much-hyped vampire in the flesh as Elijah recounts his brother's history to Elena.
A reveal this big could easily have been disappointing. However, the show pulls it off spectacularly. Not only does it pave the way for Klaus' actions in the explosive finale, but it poses several questions about the Originals for the family's future appearances in both TVD and their eventual spin-off.
Season 2, Episode 22 – As I Lay Dying (9)
There aren't many flashbacks in "As I Lay Dying", but those it does feature are extremely important. With Damon dying from a werewolf bite, he begins to hallucinate and the lines blur between the current day and the 1800s.
As he remembers what he thought were romantic moments from his human life with Katherine, Elena intrudes to tell him what he always knew – Katherine was toying with him. This episode is an important turning point in Damon and Elena's relationship, and these small moments help distinguish what makes Elena and Katherine so different.
Season 3, Episode 22 – The Departed (9.5)
According to IMDb, the season three finale isn't just the best flashback episode but the best episode of The Vampire Diaries, ever. As Damon and Stefan juggle a neutralized Klaus and a newly-turned Alaric, Elena reminisces on the final day of her life before her parents' death.
It's the first proper look viewers get at Elena pre-vampires. That alone is fascinating, but when the two timelines converge and fans witness the original accident at Wickery Bridge with the one in the current day, it feels like the show has come full circle. One version of Elena died that day with her parents. Another dies in "The Departed" as Elena finally becomes a vampire.