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

C.S. Lewis’s full given name was Clive Staples Lewis. He was born in Belfast, Ireland, on 29 November 1898, and published most of his work under the initials C.S. Lewis.

The middle name “Staples” came from his mother’s family. Lewis disliked his first name as a child and was widely known by the nickname “Jack,” a name he adopted after the death of his childhood dog, Jacksie.

Readers sometimes assume that “C.S.” represented a chosen pen name or a pair of traditional literary initials. In fact, the initials came directly from his given names. Lewis used “C.S. Lewis” for fiction, apologetics, literary criticism, and children’s literature, while friends commonly called him Jack.