The world of Narnia was finally destroyed some two hundred years later during the reign of King Tirian, son of King Erlian and seventh in descent from Rilian.
A talking ape named Shift constructed an elaborate conspiracy in a selfish attempt to change Narnia to his liking. By dressing a donkey named Puzzle in a lion's skin and claiming him to be Aslan, Shift began surreptitiously to gain control of the country, forcing inhabitants to do his bidding in the lion's name. He then made contact with the rulers of Calormen, inviting them to conquer Narnia for their mutual advantage. Calormene soldiers under Captain Rishda Tarkaan soon arrived, and by the time King Tirian learned of the ape's treasonous plans, they were well on the way to completion.
With the help of Eustace and Jill (who arrived in time to rescue the king from capture), Tirian attempted to rally Narnia and drive out the invaders, but the divisive effect of the false Aslan and the capture of Cair Paravel by a Calormene fleet rendered his efforts unsuccessful. Tirian and his remaining supporters came to a last stand against Rishda's army at the Battle of Stable Hill, where Tirian was defeated. But in the course of this final stand, the defenders were forced back into the stable, and found inside, to their surprise, Aslan's country: all that the real Narnia ever had that was good, a Narnia-within-Narnia. Aslan was waiting for them, and told them that this final defeat signified the End.
Opening the Stable door, the children and other survivors witnessed the end of Narnia, the inrushing of the sea, the destruction of sun and moon, the coming home of the stars, and ultimately the end of all that existed in the world. Aslan called all of its inhabitants to him. Those who had been faithful were taken with him into his own land where they met people who had died previously in Narnia. Those who had been unfaithful were turned away at the entrance to the new land and disappeared to an unknown fate. Aslan's land was bigger and better than the old Narnia, those who had died were found alive in it, because it was the "real" one, whereas the old Narnia had been just a copy of Aslan's land. "That was the dream, this is reality." It is also indicated that Aslan's country connected "further up and further in" to the "real" England, where Lucy Pevensie was able to see her parents, who died in a train wreck that killed all the other Pevensie siblings (except Susan) as well as Digory, Polly, Eustace, and Jill.