Clive Staples Lewis was a novelist, poet, academic, medievalist, literary critic, essayist, lay theologian, and Christian apologist. Born in Belfast, Ireland, he held academic positions at both Oxford University (Magdalen College) and Cambridge University (Magdalene College). He is best known both for his fictional work, especially The Screwtape Letters, The Chronicles of Narnia, and The Space Trilogy, and for his non-fiction Christian apologetics, such as Mere Christianity, Miracles, and The Problem of Pain.