It is based in part on the 1410 chivalric romance Il Guerrin Meschino.
In the romance of Il Guerrin Meschino, written by Andrea da Barberino about 1410, the central episode of the sixth part (Canto V) contains the "prodigious adventures" of Guerrino with this enchantress, the "Fata" Alcina, whom he seeks out, against all advice.