Who was C.S. Lewis's brother and longtime companion known as Warnie?

C.S. Lewis’s brother and longtime companion known as Warnie was Warren Hamilton Lewis.

Warren Hamilton Lewis, born in 1895, was C.S. Lewis’s older brother. Family and friends called him Warnie. The brothers shared a close relationship from childhood, and Warren remained one of Lewis’s most trusted companions throughout their adult lives.

Warren served in the British Army during the First World War and later worked as a historian. He lived with his brother for many years at The Kilns, the house outside Oxford that became strongly associated with C.S. Lewis. Warren kept diaries and later edited material connected with his brother’s life and correspondence.

Warren is sometimes confused with other members of Lewis’s literary circle, especially Owen Barfield and Charles Williams. Those men were friends and fellow participants in the Inklings, but neither was Lewis’s brother. Warren’s diaries are particularly valuable because they provide a close family perspective on Lewis’s daily routines, friendships, writing, and health.