In The Chronicles of Narnia, the youngest Pevensie child is Lucy Pevensie.
Lucy is the youngest of the four Pevensie siblings, with Peter, Susan, and Edmund older than her. In The Lion, the Witch and the Wardrobe, she is the first of them to enter Narnia after discovering the wardrobe's magical passage. Her early claim that Narnia is real is initially dismissed, especially by Edmund, but later proves true.
Lucy is characterized by her courage, compassion, and unusually strong faith. She is particularly close to Aslan and often perceives truths that her siblings struggle to accept. Across the series, she becomes Queen Lucy the Valiant, ruling Narnia alongside her brothers and sister during their visits to the world.
C. S. Lewis introduced Lucy in The Lion, the Witch and the Wardrobe, first published in 1950. She is a major character in three books—The Lion, the Witch and the Wardrobe, Prince Caspian, and The Voyage of the Dawn Treader—and remains important elsewhere in the seven-book series.