Carthya is a large kingdom situated south of Gelyn, North East of Avenia, and West of Mendenwal. The current monarch of Carthya is King Jaron Eckbert III, at the end of The Shadow Throne. Carthya's colors are Blue and Gold, and the flag is said to be the coat of arms of House Eckbert over the colors of Carthya. The capital of Carthya is Drylliad, with other major cities being Carchar, Gelvins, Libeth, Navenstill, Pyrth, Benton, and Tithio. They are allied to Bymar.
Carthya's history is not mentioned much in the books, but its past king was King Eckbert of Carthya, father of the Crown Prince Darius and King Jaron III. Its earliest mentioned king is Artolius, possibly father of Eckbert. Avenia has, for a long time, been rivals of Carthya. Mendenwal and Carthya enjoy good relations, as well as Bymar being Carthya's main ally, as a result of the betrothal of Princess Amarinda.