After the miller's daughter, Cora, proves herself to the kingdom that she is capable of spinning straw into gold, she is married to Prince Henry, and they have a daughter, Regina. Henry and Cora do not become King and Queen of that kingdom, instead they own a house and stables, where Regina is happy and has a passion for horse-riding. Henry strongly approves and encourages this, but Cora dislikes it, wanting Regina to marry a rich nobleman. Regina eventually becomes married to King Leopold, but Regina does not love him, so she carefully organizes the king's demise. Henry gives her a box with two Agrabahn Vipers in it, and Regina makes the Genie of Agrabah - who loves Regina - think that she is going to use the vipers to commit suicide. However, the Genie offers to use them to kill the king, and so he brings them to his bed where they poison and kill him. When Henry tricks Regina by presenting a false heart and claiming that it is Snow White's, Regina shrinks Henry as punishment and locks him in a box, only for Cora - now the Queen of Hearts in Wonderland - to take him away.
Regina and Jefferson manage to rescue him and Regina uses a piece of magic mushroom which reverts Henry to his normal size, before they escape Wonderland, abandoning Jefferson and leaving him behind. When Regina gathers the ingredients to cast the first Dark Curse, she finds out that she needs the heart of the thing she loves the most. Initially, she uses the heart ot her prized steed, but when she visits Rumplestiltskin, Regina realizes that she needs to kill her father. She returns to her palace, where she tells Henry that she has to kill him, tears forming in her eyes. Henry tells her that they can forget about Snow White and the curse, and start a new life instead, and be happy. Regina agrees that she can be happy, just not in the Enchanted Forest, before swiftly ripping out his heart. Regina drops Henry's heart in a fire which activates the first Dark Curse. She later manages to bury Henry and puts a headstone at the top of his grave which says "Henry, Beloved Father".
Henry reunites with Regina, who has travelled to the Underworld to rescue Captain Hook, for a brief moment. Cora has threatened to send Henry to a "worse place" than the Underworld if Regina does not leave the Underworld, but Henry begs Regina to stay in the Underworld and help the Charmings find Hook. Regina decides not to leave, and when Cora tries to banish Henry to the "worse place", it fails and instead Henry goes to Mount Olympus; although not before meeting Regina's son, Henry.
- Xavier (father)
- Cora Mills (widow)
- Regina Mills (daughter)
- Leopold White (deceased son-in-law)
- Snow White (step granddaughter)
- Henry Mills (adoptive grandson)
- Zelena Mills (stepdaughter)
- Ella "Cinderella" Mills (adoptive grandaughter-in-law)
- Lucy Mills (adoptive great-grandaughter-in-law)
- Robin (step granddaughter)
- The Miller (father-in-law)
- Henry could be loosely based on the King of Hearts from the story Alice's Adventures in Wonderland.
- In the Disney film, the King of Hearts is very small in size, which is similar to the circumstances in which Regina has Henry shrunken in size. Cora also seems to be the dominant one in their marriage, similar to the King and Queen of Hearts.
- Regina's adoptive son is named in honor of her father.
- When the first Dark Curse hits, Henry has a tomb in the Storybrooke cemetery.
- S1, E02: "The Thing You Love Most" (flashback)
- S1, E11: "Fruit of the Poisonous Tree" (flashback)
- S1, E17: "Hat Trick" (flashback)
- S1, E18: "The Stable Boy" (flashback)
- S2, E02: "We Are Both" (flashback)
- S2, E10: "The Cricket Game" (flashback)
- S2, E16: "The Miller's Daughter" (flashback)
- S4, E20: "Mother" (flashback)
- S5, E12: "Souls of the Departed"
- S5, E19: "Sisters" (flashback)
- S6, E14: "Page Twenty-Three" (flashback)
- S7, E06: "Wake Up Call" (flashback)
- Bk 5: "Regina Rising"