Prince Caspian is the first novel of a trilogy involving Caspian X. In this novel, he is a boy who has lived in a large fortress with his uncle Miraz. Caspian's father was king and brother of Miraz. Miraz had murdered Caspian's father and took his place. This means that Prince Caspian is the rightful king of Narnia, and Miraz is a usurper.

Miraz seems content to train young Caspian to be his successor until his wife gives birth to a son; then Miraz decides to murder Caspian. The Prince rushes off into the night in a perilous ride to Archenland, but he does not reckon with the Old Narnians who still lurk in the forest to the south, and some Talking Trees sweep him off his horse and leave him at the mercy of people who have the most reason to hate him and the other Telmarine humans who have ruled Narnia for ten generations.