Which C.S. Lewis novel introduces the character Edmund Pevensie?

The Lion, the Witch and the Wardrobe introduces C.S. Lewis’s character Edmund Pevensie.

Edmund enters Narnia with his siblings Peter, Susan, and Lucy after the children are sent away from wartime London. His encounter with the White Witch begins a major part of the plot: Edmund betrays his siblings after being tempted with enchanted Turkish delight, then seeks forgiveness and joins the fight against the Witch.

Edmund appears again in several later Narnia books, including Prince Caspian, The Voyage of the Dawn Treader, and The Last Battle. He is not introduced in The Magician’s Nephew, which tells Narnia’s creation and features different human characters.