member of the Umayyad ruling family of Syria who founded an Umayyad Dynasty in Spain.

When the ʿAbbāsids overthrew the Umayyad caliphate in 750 CE and sought to kill as many members of the Umayyad family as possible, ʿAbd al-Raḥmān fled, eventually reaching Spain. The Iberian Peninsula had for some time been occupied by Muslim Arab forces, and he recognized political opportunity for himself in the rivalries of the Qays and Yaman, the dominant Arab factions there. By shifting alliances and using mercenary support, he placed himself in a position of power, attacking and defeating the governor of Al-Andalus in 755 and making Córdoba his capital. As news of his success spread eastward, men who had previously worked in the Umayyad administrative system came to Spain to work with ʿAbd al-Raḥmān, and his administrative system came to resemble that formerly operative in Damascus.

ʿAbd al-Raḥmān secured his realm against external attack by defeating armies sent by Charlemagne and the ʿAbbāsid caliph. Although he faced a series of rebellions by Muslim Spaniards, Imazighen (Berbers) from the mountainous areas, and various Arab clans, his authority and dynasty remained firmly in power.