Atlantes was a powerful sorcerer featured in the chansons de geste. The sorcerer built a castle of iron in the Pyrenees to keep knights and ladies he had captured as a diversion for Ruggiero, a Saracen knight. Atlantes feared that Ruggiero would convert to Christianity and aid Charlemagne against the Saracens as he had foreseen through the use of the Book of Fates. In Orlando furioso, Atlantes constructs a magical castle filled with illusions, in order to divert Ruggiero from what he has foretold as certain doom.