The Evil Queen Regina (Lana Parrilla) is the second wife of King Leopold, whom she does not love, and the step-mother of Snow White.[5] Originally, she was the exact opposite of who she is now, and fell in love with a stable boy named Daniel (Noah Bean).

However, when Snow White was little, Regina's mother Cora caused her horse to go wayward, leading to her being saved by Regina. King Leopold wanted to marry her as thanks and to give his daughter a mother. While resolving to run away with Daniel, Snow White saw them and Regina made Snow promise not to tell her mother, but Snow is tricked into telling the secret by Regina's mother, thus leading to Cora killing Daniel and Regina being forced to marry Snow's father.[16] From then on, Regina vowed to destroy Snow's happiness to avenge Daniel.[9]

She kills King Leopold by taking advantage of the love the Genie holds for her.[5] This enacts the first part of her plan and makes her ruler of Leopold's realm.[9]

She then contrives ways to kill Snow — first by enlisting the Huntsman's help. However, the Huntsman is unable to kill her, and Regina punishes him by tearing out his heart and making him her slave. She then accuses Snow White of treason and places a bounty on her head and eventually puts her into a death-like sleep with a cursed apple.[2][9][7][13] However, Snow is awakened and she and Prince James are happily married.

On the day of the wedding, Regina vows to cast a curse on all of the inhabitants of the Enchanted Forest and take away all of their happiness so that she is the only one who is happy.[2] She previously traded this curse to Maleficent in exchange for the sleeping curse. However, she forcibly retrieves it from her only friend when negotiations go sour. She has difficulty enacting it and goes to see its creator, Rumplestiltskin, for advice.[17][4]

In exchange for the info she desires, he asks that she give him a place of comfort and respect in the "new world" the curse will send them to and that she must do anything he asks when he utters "please."

Agreeing, Regina learns she must use the heart of "the thing [she] love[s] most." She understands this to be her father Henry; with reluctance, she cuts his heart out and enacts the curse.[4] Shortly after, she travels to Snow's castle where she triumphantly exclaims to Snow White and Prince Charming that the curse is taking them "somewhere truly horrible."[2] Her desire to "win for once" fuels her endless quest for revenge.[13]

In Storybrooke, she is Mayor Regina Mills.[2] With Mr. Gold's help, she adopts Henry Mills as a baby, unbeknowst to her at first that he is really the grandson of Snow White and Prince Charming.[2][4]

However, her relationship with Henry is strained: he prefers the company of his birth mother Emma Swan, he constantly rebels, and he constantly lies to her to spend time with Emma.[2][7][4]

Because of this and after discovering who Emma really was, Regina is antagonistic toward her and is determined to keep Emma away from Henry, even going as far as to forbid Emma from seeing him without her permission and threatening to file a restraining order against Emma.[5][2][4]

Regina is also determined to convince Henry that his theory about the curse and the true identities of the Storybrooke residents is false, and she starts him on regular sessions with therapist Archie Hopper.[4]

When Archie's methods are too slow, Regina tries to force Archie to tell Henry that his idea is crazy; however, Archie refuses and threatens to declare her an unfit mother if she continues to meddle in his sessions with Henry.[8] She has a sexual relationship with Graham, really the Huntsman, but he eventually breaks up with her. Out of jealousy of Graham in taking interest and kissed Emma, she crushes his heart and kills him, revealing that she remembers her identity as the Evil Queen.[9]

Regina manipulates Emma's trust of Sidney Glass to keep an eye on Emma's activities.[5] She also tries to prevent the relationship between David Nolan and Mary Margaret Blanchard, really Prince James and Snow White, by reuniting David and his wife Kathryn, as well as using David's and Mary Margaret's affair to discredit Mary Margaret after the Nolans' marriage falls apart, and stealing Kathryn's letter stating that she never loved David and that she is allowing him to be with Mary Margaret.[7][18]

The power struggle between Regina and Rumplestiltskin continues in Storybrooke where she is constantly at odds with Mr. Gold.[10][19][20] He helps Emma run against the Regina-backed Sidney, and he has become more feared by the residents than Regina has become.[10] He eventually reveals to her that he knows he is Rumplestiltskin.

Not known to many of the residents and him, Regina is holding Belle, his true love, captive underneath the Storybrooke Hospital.[20] Despite their rivalry, Regina makes another deal with him to ensure Mary Margaret's defeat. She leaves a key in Mary Margaret's cell as he assured her that Mary Margaret would use it to escape. She becomes angry with him when she learns that Mary Margaret did as he predicted but returned to her cell after.[12]

Regina is further upset when she discovers that Gold never killed Kathryn but returns her alive. She convinces Sidney to claim to have been the one to frame Mary Margaret but Emma tells Regina she knows the truth and declares her intentions to get Henry back.[17]

During a confrontation at the school yard, Mary Margaret tells Regina she feels sorry for the other woman going out of her way to hurt others. Henry then tells Regina he knows she was the one trying to get Mary Margaret and it will not change anything as Snow and Charming will be together in the end.[1]

When Mr. Gold suggests that she may need to give up Henry to keep the curse in full strength, she replies that she simply needs to get rid of Emma. Gold declines to help her any further, so she asks Jefferson for help. She gives up the last bit of her magic so that Jefferson can use his hat to retrieve her cursed apple from the Enchanted Forest.

She succeeds in retrieving in with the last bit of magic she has left, and turned the apple into a turnover. When Emma visits her and offers to leave Storybrooke as long as Regina allows her to see Henry, she agrees to the arrangement and gives Emma the turnover as a gift for the road. When Gold deduces her plan, he reminds her that all magic comes with a price.[13]

Henry eats the turnover since Emma refuses to believe in magic or him and later he was hospitalized. Mr. Gold told Regina and Emma that to break the curse, they need to retrieve a bottle of true love. However, Mr. Gold tricks Emma into giving the bottle to him.

In the hospital, Dr. Whale said it was already too late. Emma kisses Henry's forehead, telling him she loves him, and waking him up and breaking the curse on Storybrooke. As the other characters threaten that Regina should leave as soon as possible, Regina tells Henry that she always loved him and returns home in tears. However, she smiles when she sees a magical cloud of smoke engulfing the town.[14]

In the second season, a mob arrives at Regina's house intending to kill her, but Snow and James stop them and lock Regina in a cell in the sheriff's office for her own safety. There she is confronted by Rumplestiltskin regarding her kidnapping and imprisoning Belle in the asylum, and marks her with an amulet that summons a Wraith. The Wraith attempts to suck out Regina's soul, but Snow, James, and Emma manage to get it through a portal into the Enchanted Forest, though Emma and Snow fall through as well. Henry is heartbroken by their loss, and tells Regina he never wishes to see her again until she returns them to Storybrooke[15].