C.S. Lewis’s first name was Clive. His full name was Clive Staples Lewis, although he was commonly known by his initials and by the nickname “Jack.”
Lewis was born in Belfast, Ireland, on 29 November 1898. The nickname Jack developed during his childhood after the death of a family dog named Jacksie; Lewis eventually adopted “Jack” as his preferred name. Friends and colleagues generally used it throughout his adult life.
The initials “C.S.” can cause confusion because some readers assume they stand for a different first name. They represent “Clive Staples,” not “Charles.” “Staples” was a family name inherited from his mother’s side.
Lewis later became known as a literary scholar, Christian author, essayist, and broadcaster. His best-known works include The Chronicles of Narnia, Mere Christianity, and The Screwtape Letters.