Clive Staples Lewis was a British writer, who authored more than 30 books during his prolific career, both fiction (most famously The Chronicles of Narnia) and non-fiction (including such classics as Mere Christianity and The Screwtape Letters). A professor at both Oxford and Cambridge Universities, Lewis was a contemporary with J.R.R. Tolkein, with whom he was also close friends—both were members of a group called the Inklings. Later in life, Lewis married Joy Davidman and gained two stepsons—Douglas and David Gresham. Lewis died at the age of 64 from kidney failure.