The Muslim rulers of Zaragoza, Gerona, Barcelona and Huesca, who had been cornered in the Iberian Peninsula by Abd al-Rahman I, the Emir of Córdoba, offered homage to the great king of the Franks in exchange for his military aid. Charlemagne, seeing the opportunity to extend both Christianity and his own power, agreed to head to the Iberian Peninsula.

In 778, he led the Neustrian army through the Western Pyrenees, while the Austrasians, Lombards and Burgundians crossed the Eastern Pyrenees. The armies gathered in Zaragoza, after the conquest of Pamplona, and received homage from Sulayman al-Arabí and Abu Tawr, rulers of Barcelona and Huesca but Huseyn ruler of Zaragoza reneged. Charlemagne sieged Zaragoza but after a month and faced with the strength of the walls of Zaragoza, he decided to lift the siege of the city and return to France.

As the Franks retreated across the Pyrenees back to Francia, the rearguard and cargo cars of Frankish lords were cut off and wiped out by the Vascons. The Basque attack was in retaliation for Charlemagne’s destruction of the city walls of their capital, Pamplona.

The Battle of Roncevaux Pass left several famous dead, among whom were the Seneschal Eggihard, the Count of the Palace Anselm and the Prefect of the Mark of Brittany, Roland, later inspiration for the famous Song of Roland. Roland’s death elevated him and the paladins, the foremost warriors of Charlemagne’s court, into legend, becoming the quintessential role model for knights and also greatly influencing the code of chivalry in the Middle Ages.