Originally conceived as the series' primary antagonist, by the final season Georgina came into the good graces of the Upper East Side - even becoming a member of their inner circle.

She is notable for her manipulative machinations and sudden returns throughout the series, and for appearing in all the finales, and most recently the latter half of the fifth season in light of cast members Taylor Momsen and Jessica Szohr departing.

Tim Stack of Entertainment Weekly reported that Michelle Trachtenberg took on the role that actress Mischa Barton had been previously offered.

[1][2] The Buffy alumna was cast into the role of Georgina Sparks, described by Michael Ausiello as "an adolescent Cruella".

"[2] The actress stated that the character is "basically the evil bitch from hell" and that "She's been part of the Gossip kids' lives for a long time, and she's coming back around to make her presence known.

She has stated that the character is "incredibly evil, manipulative and pretty much just takes no prisoners, and she doesn't care about the consequences.

"[6] Trachtenberg also draws her on her "own painful teen experience in her L.A. private school," citing her work on Harriet the Spy as an inspiration for her portrayal of the character.

[7] Georgina Sparks, a girl who had frequently partied with Serena van der Woodsen, returns to New York from Switzerland.

Georgina is first mentioned in "The Blair Bitch Project" when Serena discovers that she had been sending her packages of champagne, porn, sex toys and drugs—not Chuck.

Since she had missed her study date with Dan, Chuck helps Serena conceal the truth—claiming she had suffered from food poisoning the previous night.

Georgina packs her bags to leave Manhattan until Serena confronts her, seeking to end their friendship, having realized that she makes too many mistakes when she's around her.

Unfortunately for Serena, Georgina changes her mind, unpacks her bags and meets Dan in Central Park while introducing herself as Sarah.

[10] Chuck lost his virginity to Georgina in sixth grade; he recalls her partying attitude before Serena abruptly left for boarding school.

However, Georgina has successfully deceived Dan by confessing her real name and a tale about needing the identity of Sarah.

[14] Georgina was in fact in a rehabilitation center in Utah where she escaped, hitchhiked into a town, stole a credit card and booked a ticket to Ibiza.

Georgina unfortunately loses the money that she intended to buy Bibles for Christian children to Poppy, Blair accuses her of sabotaging the plan and that she will never be forgiven by Jesus as well as herself.

Georgina, upset and adamant that she didn't do anything wrong, reverts to her old self at the end of the episode, with the intent of getting her money back.

[22] The third-season finale has Georgina return from Belarus wearing a blond wig and large coat, desperately seeking the help of various Upper-East Siders with her "problem."

In the season premiere "Belles de Jour" it is revealed Georgina had a son, Milo, born on July 7, 2010, but it is unknown if Dan Humphrey is the father at first because they never did a DNA test.

Whilst she is away, Rufus does a DNA test himself, and breaks the news to Dan that he isn't Milo's biological father.

She reveals to Serena that she is living in Bedford, New York and is now married, but bored, from the lifestyle she sought to raise her son in.

She is caught inside the church by Rufus and Lily who have her thrown out, but not before she ends up recording Blair's confession of love to Chuck before the wedding commences.

After taking her camera back from Serena, Georgina is seen putting up a video of Blair and Louis leaving for their honeymoon.

Phil appears to love Georgina and knows all about her past and of her agenda against everyone she knows on the Upper East Side and he assists her in times of need despite the fact that she often treats him badly and ignores their baby, Milo, leaving Phil as the parental caregiver at home while she goes out to work her ways.

Following Blair's return from her honeymoon, Georgina learns that Ivy is back in town and goes to the Van der Woodsens' to confront her.

While at a party thrown by Nate, Dan discovers that she is Gossip Girl and he blackmails her with this information as she is trying to get Blair to default on her marriage to Louis, thereby effectively ruining her family's financial security.

Dan, having seemingly been dumped by Blair, alienated and betrayed by Serena, Lily, Chuck, Nate and everyone that he knows, approaches Georgina, asking for help to publish the sequel to "Inside", pledging to write the novel "he should have written from the beginning".

CNN included the introduction of Georgina in the list of the series' "OMG" moments, writing that she is "the kind of insane yet hilarious character that can make any episode better.

"[24] BuddyTV found Georgina "amazing" in the 100th episode, "you can't even take your eyes off her because she's so great in every scene.