Edmund Pevensie is the second son and third child of Mr. and Mrs. Pevensie. When he is around ten years old, he and his siblings are sent to live with Professor Kirke in the country because of the London bombings of World War II. Edmund is resentful of Peter's and Susan's authority, and vents his frustrations on Lucy. When Lucy claims to have found Narnia in the Wardrobe, Edmund teases her relentlessly about it. When Edmund finds himself in Narnia after following Lucy into the Wardrobe, he meets the White Witch and gorges himself on enchanted Turkish Delight. He agrees to bring his siblings to her in exchange for being made Prince of Narnia. Edmund keeps this a secret from the others after he finds Lucy and they return to England. There, he betrays Lucy by denying that he visited Narnia, making it look like she is either a foolish child or a deliberate liar.
When all four Pevensies stumble into Narnia, Edmund leaves them at the Beavers' house to go to the White Witch. There he betrays them by telling her where they are. All too late, Edmund realizes that she is evil, and he suffers much abuse at her hands until Aslan sends a group of Narnians to rescue him. But the White Witch will not give up her captive easily, and visits Aslan's Camp to insist that Edmund's blood belongs to her. Aslan arranges matters to free Edmund from her power. It is uncertain if Edmund ever learns that Aslan's sacrifice was part of the bargain with the Witch. During the Battle of Beruna, Edmund succeeds in damaging the Witch's power by breaking her wand, but is severely wounded. He lies near death until Lucy heals him with her magic cordial. Later he is crowned King Edmund the Just at Cair Paravel, where he and his siblings reign in Narnia for 15 years.
Edmund is a key player in the Calormen-Archenland conflict of 1014 (1941 in England) when he and several other Narnians manage to avoid capture in Calormen. Edmund leads the Narnian forces at the conflict at Anvard. Edmund and his siblings stumble back into our world later in 1014 while hunting the mythical White Stag.
A year later (in England time) Edmund and his siblings are called back into Narnia by Susan's horn, blown by Prince Caspian. There, they help Caspian free Narnia from its oppression under the Telmarines. Once this is accomplished, Aslan sends the Pevensies back home with the understanding that Edmund and Lucy will return some day.
That day comes a year later (1942), when Edmund, Lucy, and their cousin Eustace enter Narnia through a painting in Eustace's home. There they meet Caspian aboard the Dawn Treader. Eustace assists Caspian in his quest to find the seven missing lords, and serves as a mentor to his cousin after Eustace reforms. After many adventures, Edmund, Lucy, and Eustace sail to the end of the world where they meet Aslan. There Edmund is told that he has grown too old for Narnia. He then goes home to England for the last time.
Seven years later, when Edmund was 19 (1949 England time), he and his siblings are brought to Narnia for the last time. There had been a serious railways accident, and their lives on Earth have ended. But the real story has just started, and Edmund joins the others to go "Further up and further in!" in Aslan's country.