He had arrived from Spain, together with other Saracens in his train, to surrender to the king of the Franks himself and all the towns which the king of the Saracens had confided to his keeping." For a long time past the Christians of the West had given the Mussulmans, Arab or other, the name of Saracens.

Ibn-al-Arabi was governor of Saragossa, and one of the Spanish Arab chieftains in league against Abdel-Rhaman, the last offshoot of the Ommiad khalifs, who, with the assistance of the Berbers, had seized the government of Spain.

Amidst the troubles of his country and his nation, Ibn-al-Arabi summoned to his aid, against Abdel-Rhaman, the Franks and the Christians, just as, but lately, Maurontius, duke of Arles, had summoned to Provence, against Charles Martel, the Arabs and the Mussulmans.
Charlemagne accepted the summons with alacrity.

With the coming of spring in the following year, 778, and with the full assent of his chief warriors, he began his march towards the Pyrenees, crossed the Loire, and halted at Casseneuil, at the confluence of the Lot and the Garonne, to celebrate there the festival of Easter, and to make preparations for his expedition thence.

As he had but lately done for his campaign in Italy against the Lombards, he divided his forces into two armies one composed of Austrasians, Neustrians, Burgundians, and divers German contingents, and commanded by Charlemagne in person, was to enter Spain by the valley of Roncesvalles, in the western Pyrenees, and make for Pampeluna; the other, consisting of Provenccals, Septimanians, Lombards, and other populations of the South, under the command of Duke Bernard, who had already distinguished himself in Italy, had orders to penetrate into Spain by the eastern Pyrenees, to receive on the march the submission of Gerona and Barcelona, and not to halt till they were before Saragossa, where the two armies were to form a junction, and which Ibn- al-Arabi had promised to give up to the king of the Franks.