Alfonso II (759-842, king 791), Alfonso I's reputed grandson, bears the name of "the Chaste."
The Arab writers who speak of the Spanish kings of the north-west as the Beni-Altons, appear to recognize them as a royal stock derived from Alfonso I.
The events of his reign are in reality unknown. Poets of a later generation invented the story of the secret marriage of his sister Ximena with Sancho, count of Saldana, and the feats of their son Bernardo del Carpio. Bernardo is the hero of a cantar de gesta (chanson de geste) written to please the anarchical spirit of the nobles.