Some confusion exists about his names and titles. Juan Manuel often refers to himself in his books as "Don Juan, son of infante don Manuel". But some 19th and early 20th century scholars started calling him infante, a title he did not possess, as in medieval Castile only the sons of kings were called infantes (and he was the grandson of Fernando III). The same applies for the title of Duke and Prince of Villena, that he received from Alfonso IV and Pedro IV of Aragón. While these titles follow the Aragonese nobiliary traditions, they were of little interest to the Castilian author, to the point that he never used them in his writings or correspondence, and they have only been associated to him by a handful of scholars.