Who was C.S. Lewis’s elder brother and lifelong correspondent?

C.S. Lewis’s elder brother and lifelong correspondent was Warren Lewis.

Warren Hamilton Lewis, commonly known as Warnie, was born in 1895, three years before his younger brother. The brothers remained close throughout their lives and shared interests in history, literature, and military affairs. Warren later became a historian and wrote extensively about seventeenth-century France.

Warren served in the British Army during the First World War and later worked for the Ministry of Pensions. His diaries and letters provide important evidence about C.S. Lewis’s daily life, friendships, religious development, and academic career. The brothers also lived together for many years at The Kilns near Oxford.

Warren is sometimes confused with Albert James Lewis, their father, or with Lewis’s literary friends Owen Barfield and Charles Williams. Unlike those figures, Warren was Lewis’s brother and a regular personal correspondent. His records remain an important source for modern biographers.