What was C.S. Lewis’s real first name?

C.S. Lewis’s real first name was Clive.

Lewis was born Clive Staples Lewis in Belfast on 29 November 1898. As a child, he was known by the nickname “Jacks,” which became the name used by many friends and associates throughout his life. The nickname reportedly arose after the death of his dog, which he associated with the name Jacksie.

The initials C.S. stand for Clive Staples. Lewis generally published under his initials rather than using his first name, helping create the familiar author name C.S. Lewis. “Staples” was his mother’s family surname and became his middle name.

His public identity is therefore easy to misread. C.S. does not stand for Charles or Christopher, and “Jacks” is a nickname rather than his legal first name. The initials became internationally associated with The Chronicles of Narnia, Christian apologetics, literary criticism, and science fiction.