This archive contains personal letters between Warren H. Lewis (1895-1973), the elder brother of C.S. (Jack) Lewis and various correspondents. Warren lived with C.S. Lewis for many years in their Oxford home, The Kilns, and served as a personal secretary helping his brother answer his extensive correspondence until Jack's death in 1963. Some of the correspondents in this letter collection began corresponding with C.S. Lewis and subsequently met and continued corresponding with Warren Lewis as well.

Warren was born in Belfast, Ireland and was sent to boarding schools in England before entering the Royal Military Academy at Sandhurst in 1914. His military service spans both World Wars and his travels included stations in France and China. After his retirement, Warren became a scholar in his own right, publishing a number of highly regarded historical works.