Clive Staples Lewis (C. S. Lewis) was a British writer and lay theologian. He held academic positions in English Literature at both Oxford University (Magdalen College, 1925–1954) and Cambridge University (Magdalene College, 1954–1963). He is best known for his works of fiction, especially The Chronicles of Narnia, and for his non-fiction Christian apologetics, such as Mere Christianity, The Screwtape Letters, and The Problem of Pain.

Born in Belfast, Ireland, on 29 November 1898, Lewis was the son of Albert James Lewis, a solicitor, and Florence Augusta Hamilton Lewis. He had an elder brother, Warren Hamilton Lewis. The family home, Little Lea, in east Belfast, was a large house with a sprawling garden that fostered the boys' imaginative worlds. Lewis's mother died when he was young, and he subsequently attended various schools in England.

Lewis served in the British Army during World War I, sustaining injuries in the Battle of Arras. After the war, he returned to Oxford, where he earned a First in Greats (Classics) and a First in English Language and Literature. He became a Fellow and Tutor in English Literature at Magdalen College, Oxford, in 1925, a position he held for 29 years.