According to this plan, Charlemagne had to traverse the territories of Aquitaine and Vasconia, domains of Duke Lupus II., son of Duke Waifre, so long the foe of Pepin the Short, a Merovingian by descent, and in all these qualities little disposed to favor Charlemagne.

However, the march was accomplished without difficulty.

The king of the Franks treated his powerful vassal well; and Duke Lupus swore to him afresh, "or for the first time," says M.Fauriel, "submission and fidelity; but the event soon proved that it was not without umbrage or without all the feelings of a true son of Waifre that he saw the Franks and the son of Pepin so close to him." The aggressive campaign was an easy and a brilliant one.

Charles with his army entered Spain by the valley of Roncesvalles without encountering any obstacle.

On his arrival before Pampeluna the Arab governor surrendered the place to him, and Charlemagne pushed forward vigorously to Saragossa.