The Crown Prince is the next in line to become King in many kingdoms. Alexander was the Crown Prince of Daventry. It is unclear if he remained Crown Prince of Daventry after becoming King of the Green Isles. Some suggest that instead his sister (the Princess of the Realm) went on to become the next heir (since Alexander had already become a king of the Green Isles), as she was before Alexander's return, and before her attempted sacrifice to the Three-headed Dragon. In other stories, Gwendolyn is competed to become the next heir, against her cousin Gart.