The Maghreb fell into a civil war in 739 that lasted until 743 known as the Berber Revolt. The Berbers revolted against the Umayyads, putting an end to Eastern dominion over the Maghreb. Despite racial tensions, Arabs and Berbers intermarried frequently. A few years later, the Eastern branch of the Umayyad dynasty was dethroned by the Abbasids and the Umayyad Caliphate overthrown in the Abbasid revolution (746-750). Abd al-Rahman I, who was of Arab-Berber lineage, managed to evade the Abbasids and flee to the Maghreb and then Iberia, where he founded the Emirate of Córdoba and the Andalusian branch of the Umayyad dynasty. The Moors ruled northern Africa and Al-Andalus for several centuries thereafter. Ibn Hazm, the polymath, mentions that many of the Caliphs in the Umayyad Caliphate and the Caliphate of Córdoba were blond and had light eyes. Ibn Hazm mentions that he preferred blondes, and notes that there was much interest in blondes in al-Andalus amongst the rulers and regular Muslims: