Which Narnia novel did C.S. Lewis publish last?

The Narnia novel C.S. Lewis published last was The Last Battle.

The Last Battle was published in 1956 by The Bodley Head. It is the seventh and final published volume of The Chronicles of Narnia, although Lewis’s internal chronology places some other books earlier in Narnian history. The plot centers on a false Aslan, a conflict over Narnia’s identity, and the end of the world of Narnia.

The novel won the Carnegie Medal in 1957, a major British children’s book award. Lewis dedicated it to his goddaughter Lucy Barfield, whose name also inspired the character Lucy Pevensie. The dedication gives the book a direct connection to the young readers for whom Lewis wrote.

The Last Battle is often confused with The Magician’s Nephew because that book explains Narnia’s beginning. Publication order, however, makes The Last Battle the final volume released by Lewis.