Sulayman al-Arabi the pro-Abbasid Wali (governor) of Barcelona and Girona sent a delegation to Charlemagne in Paderborn, offering his submission, together with the allegiance of Husayn of Zaragoza and Abu Taur of Huesca in return for military aid.[9] The three pro-Abbasid rulers also conveyed that the caliph of Baghdad, Muhammad al-Mahdi, was preparing an invasion force against the Umayyad ruler Abd al-Rhaman I.[9]