The medieval French chivalric romance, which narrates the adventurous life of Messire Charles de Hongrie, that is, Lord Charles of Hungary, and was written for being read aloud, presents through the figure of its hero the ideal knight to the presumed audience, the inhabitants of the French noble manors. The author of the romance as well as the place and time of its birth are unknown; it has survived in a single manuscript, presumably from the 16th century. Both the heroes and the scenes of the story are purely fictitios, and on the basis of the events concerning Hungary it is evident that the author knew nothing about Hungary. Yet it is not the only fictional history with regard to a Hungarian prince or princess. In general, none of the Hungarian princes or princesses has anything to do with real Hungarian history. It was merely in order to enhance the authority of their heroes that the authors of these histories represented them as members of dynasties which were little known to their readers but enjoyed fairly general reputation throughout Europe. In the late Middle Ages, that is, the 14th and 15th centuries, the Kingdom of Hungary was especially fit for this role, as is proved by the romances and legends cited in the present paper.