What was C.S. Lewis's final published Narnia novel?

The Last Battle was C.S. Lewis's final published Narnia novel.

The Last Battle was published in 1956 and is the seventh book in The Chronicles of Narnia. It depicts the final conflict in Narnia and brings the series' large narrative arc to its conclusion. The story includes King Tirian, a false representation of Aslan, and the destruction of the old Narnian world.

Lewis received the Carnegie Medal for The Last Battle in 1957. The award is presented annually by the Chartered Institute of Library and Information Professionals for an outstanding book for children or young adults published in the United Kingdom.

The final novel is sometimes confused with The Magician's Nephew because that book explains the creation of Narnia and is first in the internal chronology used by many modern editions. Publication order is different: The Lion, the Witch and the Wardrobe came first in 1950, while The Last Battle closed the original sequence in 1956.