Clive Staples Lewis (1898-1963) was one of the intellectual giants of the twentieth century and arguably the most influential Christian writer of his day. He was a fellow and tutor in English literature at Oxford University until 1954, when he was unanimously elected to the chair of Medieval and Renaissance English at Cambridge University, a position he held until his retirement. His major contributions to literary criticism, children's literature, fantasy literature, and popular theology brought him international renown and acclaim. Lewis wrote more than thirty books, allowing him to reach a vast audience, and his works continue to attract thousands of new readers every year. His most distinguished and popular accomplishments include the Chronicles of Narnia, Out of the Silent Planet, The Four Loves, The Screwtape Letters, and Mere Christianity.