Juan Manuel, Prince of Villena
Don Juan Manuel, Prince of Villena, grandson of King Ferdinand III, wrote in his "Libro de los ejemplos del conde Lucanor y de Patronio" (1337) ("Book of the examples of Count Lucanor and of Patronio"), that Lobera was the sword of Fernán González of Castile (epic hero from the Poem of Fernán González) and a "sword of great virtue". Don Juan Manuel writes that King Ferdinand III, lying on his deathbed, addressed him in these words: "I can bequeath no heritage to you, but I bestow upon you my sword Lobera, that is of passing worth, and wherewith God has wrought much good to me." .