Clive Staples Lewis (1898-1963) was one of the intellectual giants of the twentieth century and arguably one of the most influential writers 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 Literature at Cambridge University, a position he held until his retirement. He 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 Out of the Silent Planet , The Great Divorce , The Screwtape Letters , and the universally acknowledged classics in The Chronicles of Narnia. To date, the Narnia books have sold over 100 million copies and have been transformed into three major motion pictures.