How does Edmund's character change over the story

Edmund is the second youngest of the children, and is cruel to his younger sister, Lucy, making fun of her story about the wardrobe and Narnia. Peter and Susan both feel that Edmund is becoming a "bad sort".

Edmund is the second of the children to reach Narnia, and while traveling alone meets the White Witch, who brings him under her spell using enchanted Turkish Delight. His extraordinary craving ultimately leads Edmund to betray his brother and sisters to the White Witch. He informs the witch about the whereabouts of his siblings, and tells her about Aslan's arrival and the meeting at the Stone Table. He is consistently characterized as a skeptic, asking how the others can be certain that the faun is good, that the robin is benevolent, and that the beavers are their friends. In the end, however, Edmund realizes the extent to which he has misjudged the White Witch, and rejoins his brother and sisters. He apologizes and receives their forgiveness, but since he has betrayed the promise that he made to the White Witch, she has the right to kill him. Aslan promises the White Witch that he will die in Edmund's place; in the end, it is unclear whether or not Edmund ever knows the full extent of Aslan's loyalty. Edmund proves his valor by destroying the witch's wand. He is injured in the fray, but when he recovers Aslan makes him a Knight.

When Edmund becomes King, he is lauded for his counsel and judgment, and is known as "Edmund the Just."