The Castilian fourteenth-century author Don Juan Manuel is most renowned for his frame-tale collection of exempla, the Conde Lucanor (1335), but he wrote numerous works of fiction and history, always in a didactic vein. This article examines certain ‘reality elements’ in the fictional and historical tales of the Conde Lucanor and other works of its author, principally the use of autofiction and the insertion of historical figures in a fictional setting or their use in such a mode. This topic is approached through wider discussions about the distinction between allegorical and historical truth in Juan Manuel’s work, the discursive common ground between medieval history and fiction in terms of their plausibility, and the notion of the purported self-referentiality of fiction. It is argued that autofictional and other reality elements are not so much an attempt to verify or authenticate otherwise fictional narratives, as it is a conscious play on the common ground of the historical and the fictional mode, and part of a cohesive didactic strategy on the part of the author in question – interconnected with his social and political position in fourteenth-century Castile.