Kaspian is a K-spelling of Caspian, the great inland sea between Europe and Asia, which was named after the ancient Caspi people who lived on its shores, so the name means "from the Caspian Sea". Parents know it above all from Prince Caspian, the young king of C. S. Lewis's Narnia books, and the Danish Kasper gives the K spelling a Scandinavian feel. Kaspian had fewer than five births in 2000 and has climbed from number 6147 in 2015 to number 2663 in 2025, its best rank so far, with 49 boys.