Clive Staples Lewis, Jack to his friends, was born in Belfast on 29 November 1898. A solicitor's son, educated mostly in England, he won a classical scholarship to Oxford University in 1916. Enlisting in the army, he was wounded at Arras in 1918. On resuming his studies, he entered into a curious relationship with a demanding older woman, Janie Moore, following a promise made to her son who was killed in the war.

Despite the financial burden, Lewis set up home with Mrs Moore and her daughter, first in Oxford and later at nearby Headington Quarry. In 1932 they were joined by Lewis' elder brother Warnie, who had retired from the army. Lewis remained in the house after Mrs Moore's death in 1951 and in 1956 married an American divorcee, Joy Davidman, to enable her to avoid extradition. This second curious relationship brought unexpected happiness, but his wife died of bone cancer in 1960, and Lewis himself died at home on 29 November 1963.

With a triple first, Lewis became a fellow and tutor of Magdalen College in 1925. An agnostic, he found his views changing, helped by the vigorous discussions of academics known as the Inklings, notably J. R. R. Tolkien. From theism he came to a full acceptance of Christianity - 'the most dejected and reluctant convert in England', he later wrote. In 1936 he won the Hawthornden prize with The Allegory of Love, but it was The Screwtape Letters (1942) which made him internationally famous, together with broadcast talks, later collected as Mere Christianity (1952). Screwtape is an elderly devil advising his apprentice nephew, who is having trouble securing the damnation of a young Christian.

Lewis' predominance as a Christian apologist probably hindered his academic career, but following his monumental English Literature in the Sixteenth Century (1954), he was appointed to a new Cambridge chair in Medieval and Renaissance English, though he returned regularly to his Oxford home. A science fiction trilogy was followed by the great success of The Chronicles of Narnia (1950-56), seven children's books beginning with The Lion, the Witch and the Wardrobe. His autobiographical work, Surprised by Joy (1955), describing his conversion to Anglo-Catholicism, was also a bestseller. Lewis' marriage to Joy Davidman inspired William Nicholson's play Shadowlands (1989), and his unusual life continues to attract biographers and critics.