Matruh, together with his father Sulayman al-Arabi, joined Charlemagne's army to besiege Zaragoza in 778. When Zaragoza failed to surrender, Charlemagne took hostages from his allies, including Sulayman al-Arabi. Matruh and his brother Aysun allied to the Basques, and at the Battle of Roncevaux Pass they ambushed Charlemagne's baggage train, releasing their father.