A character in C.S. Lewis' The Chronicles of Narnia, Peter was High King of Narnia in its golden age. He and his siblings Susan, Edmund and Lucy shared the distinction of having lived two full lifetimes -- in Narnia and our world.
At first Peter did not believe Lucy when she told the others that she had found another world in the back of a wardrobe in Professor Digory Kirke's old house, but he soon discovered Narnia for himself when the four hid in the wardrobe from an unpleasant housekeeper. Once in Narnia, Peter found himself swearing fealty to Aslan and fighting alongside Narnia's Talking Beasts against the forces of Jadis, the White Witch. After their victory, Aslan named the four as Narnia's kings and queens, reigning in the castle Cair Paravel; as the eldest, Peter was named High King. They reigned for many years, until after a hunt for the White Stag they found themselves back in Professor Kirke's house, returned to their former ages. (The Lion, The Witch, and the Wardrobe)
Magically called back to Narnia, Peter and the others found themselves a thousand years in its future, this time joining Prince Caspian in his struggle to take the Narnian throne from the usurper King Miraz. Peter challenged Miraz to single combat, and held his own against the bigger, stronger Telmarine until the battle was interrupted by Miraz' lieutenants' own treachery. Miraz was defeated, and Caspian was made king.
Aslan told Peter that this would be his last visit to Narnia; he and Susan were becoming too old.
Years later, Peter, Edmund, Lucy and four other Friends of Narnia were dining when the apparition of Narnian King Tirian visited them. Realizing that Narnia needed their help, Peter and Edmund retrieved the magic rings that originally transported people of Earth to Narnia. They were bringing them to the others by train when a horrible rail accident occurred. Peter and the others found themselves plucked away to another, more perfect Narnia, and witnessed the final hours of the Narnia he had known. (The Last Battle)
Peter was knighted Sir Peter Fenris-Bane by Aslan after his first battle with the White Witch's lieutenant Fenris Ulf, a Talking Wolf.