Which C.S. Lewis novel begins with a magical wardrobe leading children into another world?

The C.S. Lewis novel that begins with a magical wardrobe leading children into another world is The Lion, the Witch and the Wardrobe.

Published in 1950, the book follows Peter, Susan, Edmund, and Lucy Pevensie after they are sent away from London during the Second World War. Lucy discovers that the back of a wardrobe opens into Narnia, a land trapped in winter under the rule of the White Witch. Her siblings later enter Narnia and become involved in its conflict.

The book was the first published Narnia novel, although many modern editions number The Magician’s Nephew first because it tells an earlier part of Narnia’s history. Lewis wrote The Magician’s Nephew later, and its publication order is therefore different from its internal chronology.

The wardrobe itself was inspired in part by Lewis’s interest in imaginative stories and by memories of childhood reading. The novel combines talking animals, classical mythology, medieval romance, and Christian imagery. Its title refers to the three central figures: Aslan, the witch, and the four children.