Which radio program first broadcast C.S. Lewis’s wartime Christian talks?

C.S. Lewis’s wartime Christian talks were first broadcast on the BBC Home Service.

The talks began in 1941, during the Second World War, and were delivered for radio listeners rather than as a single book manuscript. Lewis later revised and collected the material, which became the influential work Mere Christianity. The broadcasts presented arguments about morality, belief, and Christian doctrine in language intended for a broad audience.

The name Mere Christianity belongs to the later book and its collected broadcast material, not to the original radio series title. The talks helped make Lewis a recognizable public speaker beyond academic and literary circles. Major sections were broadcast in several series between 1941 and 1944, while the BBC Home Service was the network carrying the original talks.