There was an Abbasid–Carolingian alliance during the 8th and 9th centuries, effected through a series of embassies, rapprochements and combined military operations between the Frankish Carolingian Empire and the Abbasid Caliphate. The alliance is likely to have formed first between Pepin the Short and al-Mansur, and later to have continued under Charlemagne and Harun al-Rashid. These contacts followed the intense conflict between the Carolingians and the Emirate of Córdoba, marked by the Battle of Tours in 732, and were aimed at establishing a counter-alliance with the 'faraway' Abbasid Empire based in the Near East. Slightly later, another Carolingian-Abbasid alliance was attempted in a conflict against the Byzantine Empire. Primary sources Direct evidence for Abbasid–Carolingian diplomacy comes almost entirely from Frankish (Latin) sources. These are mostly contemporary or nearly so. Especially important are the quasi-official Royal Frankish Annals, Einhard's Vita Karoli magni and the anonymous Vita Hludowici imperatoris. There is also indirect evidence. Charlemagne's elephant is referenced by Dicuil, an Irishman writing around 825. Likewise, the Basel roll, a record of a survey of the church in the Holy Land commissioned by Charlemagne, corroborates Einhard's account. The absence of references to Abbasid–Carolingian diplomacy in Islamic sources is not peculiar. The major Arabic history of the period, that of al-Ṭabarī, routinely records relations only with the Byzantine Empire. Otherwise routine diplomacy that went smoothly goes unreported. There is no reference to diplomatic contacts with Tang China, for example, which is known directly only from Chinese sources. There is only one contemporary source from the Abbasid Caliphate that refers to diplomacy with Charlemagne, versions III and IV of the Arabic Sibylline prophecy, which were redacted in the aftermath of Harun's death. Background The Umayyad invasion of Gaul from 719 to 759 was a period of intense conflict between the Carolingians and the Umayyads, marked by the Battle of Tours in 732. Umayyad forces were finally expelled from Gaul with the conquest of Narbonne in 759 by Pepin the Short, but the Umayyad presence in the Iberian peninsula continued to represent a challenge to the Carolingians. Pepin the Short and al-Mansur Embassies Contacts between the Carolingians and the Abbasids started soon after the establishment of the Abbasid Caliphate and the concomitant fall of the Umayyad Caliphate in 751. The Carolingian ruler Pepin the Short had a powerful enough position in Europe to "make his alliance valuable to the Abbasid caliph of Baghdad, al-Mansur". Former