What was C.S. Lewis’s full legal name?

C.S. Lewis’s full legal name was Clive Staples Lewis. He was born on 29 November 1898 in Belfast, Ireland, then part of the United Kingdom. The initials “C.S.” came from his first two names, Clive Staples, rather than from a shortened middle name or a pseudonym.

Lewis disliked being called Clive from childhood and adopted the nickname “Jack.” The name came from a childhood dog named Jacksie, which was killed by a car; Lewis later used “Jack” for the rest of his life. Friends, students, and colleagues generally knew him by that nickname.

His brother Warren was also commonly called Warnie. Lewis became a major literary scholar, Christian apologist, and author of fiction, including The Chronicles of Narnia. A frequent mix-up is assuming that “C.S.” means a pen name, but it was simply his initials.