What was the name of C.S. Lewis’s brother and longtime housemate?

C.S. Lewis’s brother and longtime housemate was Warren Lewis.

Warren Hamilton Lewis, usually called Warnie, was born in 1895 and was C.S. Lewis’s older brother. The brothers remained close throughout their lives, despite periods of tension and the disruption caused by military service and Lewis’s early education.

Warren served in the British Army during the First World War and later worked as a historian. He kept extensive diaries, which became an important source for understanding C.S. Lewis’s daily life, friendships, travels, and writing.

The brothers lived together for many years at The Kilns, the Oxford home associated with Lewis. Warren also belonged to the Inklings’ wider circle, although he was not the group’s best-known literary figure. Readers sometimes confuse him with Lewis’s father, Albert James Lewis, or with Lewis’s tutor William Kirkpatrick.