Edmund comes from a long line of monarchs and warriors that have sworn to protect the world from the Moonstone, a powerful stone created by a single drop of moonlight that harnesses the power of death and destruction. When Edmund assumed the throne, he also assumed the destiny of his ancestors by devoting himself to keeping the Moonstone's power at bay. In the midst, Edmund's wife gave birth to a baby boy, Eugene. During Eugene's infancy, Edmund grew tired of the damage caused by the Moonstone and tried to destroy it once and for all. However, upon doing so, the Dark Kingdom was nearly destroyed in a catastrophic event that killed the queen. Riddled with guilt and determined to keep his surviving subjects safe, Edmund ordered for a kingdom-wide evacuation. Eugene was taken away by a servant woman and placed in an orphanage. Edmund sent ravens to watch over his son, but eventually they lost track of him, but they would bring Eugene's wanted posters to comfort him.
Meanwhile, Edmund's most trusted warriors (Quirin, Adira, and Hector) formed a group known as the Brotherhood that was sworn to keep all away from the Moonstone. Edmund, meanwhile, remained in the Dark Kingdom to keep the stone's magic out of the wrong hands.
Role in the series
When Rapunzel's party arrived in "Destinies Collide", Edmund tried to send the group to their doom, by cutting the line to a gondola carrying them. He stopped himself from killing his son when he realized who he was because of his eyes. Happy to be reunited with his son, he explained to him the legacy of the Dark Kings in keeping the moonstone's power in check, revealing how it killed his wife in an effort to show why Eugene couldn't let Rapunzel near it.
Later in a climatic battle with his ancestors, he was asked by his son to have faith in Rapunzel. He helped defeat the ghost of his ancestors and allowed Rapunzel, Eugene, and Cassandra inside the moonstone room in hope to end destruction for once and all.