Thence his line stretched along the Pyrenees by the passes of Vera, Echallar, Maya and Roncesvalles, to Altobiscar; his immediate object now being to reduce the fortresses of San Sebastian and Pampeluna.
It was useless to attempt to avenge this disaster, which occurred on the 15th of August 778, for the enemy disappeared as quickly as he came; the incident has passed from the domain of history into that of legend and romance, being associated by tradition with the pass of Roncesvalles.
He had not visited Spain since the disaster of Roncesvalles, but he continued to take a lively interest in the affairs of that country.
The account in the Chanson de Roland of the trial of Ganelon after the battle of Roncesvalles must have been adopted almost intact from earlier poets, and provides a striking example of the value of the chansons de geste to the historian of manners and customs.
The traditions of Charlemagne's fights with the Norsemen (Norois, Noreins) are preserved in Aiquin (12th century), which describes the emperor's reconquest of Armorica from the " Saracen " king Aiquin, and a disaster at Cezembre as terrible in its way as those of Roncesvalles and Aliscans.