711 was a key year in Spanish history. That was when Muslim forces crossed the straits of Gibraltar, defeated a Visigothic army somewhere west of Gibraltar, and moved quickly northwards. Within a few years the Moors (the name applied to the newcomers, irrespective of ethnic origin) had conquered almost all of the Iberian Peninsula, and Christian Hispania was transformed into Muslim al-Andalus (as the Muslims called the land they occupied). Or, more accurately, control of the peninsula passed to new hands, because the effect on most of the population, especially in rural areas, would have been minimal. Conversion to Islam would take time.
Christian Visigothic response to the conquest varied. Some leaders resisted and were summarily executed e.g. in Córdoba, Toledo, Mérida, Zaragoza. Some signed agreements with the invading forces in return for which they were free to follow their Christian practices, subject to certain restrictions. Some fled to the mountainous regions of the north, and finally others converted to Islam. These latter were known as Muwallads, literally “those born of two races.” (Another term sometimes used was Muladi.)
The rate of conversion initially was probably not very large, with the percentage of converts by 800 being estimated at about only 10%, mostly in urban areas. Why the slow rate of conversion? First, the conquest was an ongoing venture with expansion northwards even beyond the Pyrenees, leaving little time or opportunity for active proselytising. Second, up to the arrival of Abd al-Rahman (I) in 756, al-Andalus was politically unstable owing to internal tribal rivalries between Arabs (the elites of the invaders), and discontent and revolt amongst the Berber troops, who made up the bulk of the soldiers.
Conversion increased significantly during the 9th century (sufficient to cause concern among devout Christians) and continued throughout the 10th century. By 1000, the percentage of converts probably reached 75-80%.
Apart from relatively isolated cases, conversion in the early years was probably stimulated mainly by intermarriage between Muslim soldiers and Christian women. The wives would naturally adopt the faith of their husbands, and since descent was patrilineal (following the male line), their children would automatically be Muslims. Even at the highest level intermarriage in this early period was not unknown. We have an early example in Abd al-Aziz, governor of al-Andalus from 712 to 715, who married a Christian, reputedly none other than the widow of Roderic, the last Visigothic king. Al-Aziz met a sticky end, assassinated in 716; interestingly, one of his assassins, Ziyad ibn Nabigha, had also taken a Christian wife.
Abd al-Rahman I’s authoritative rule (756-788) undoubtedly made it clear that the Moors were in al-Andalus to stay. It also provided stable conditions more conducive to social interaction which could lead to conversion. Significantly, it was towards the end of his reign (785) that Abd al-Rhaman I authorised the construction of the Great Mosque, later added to in the following centuries. It signalled that there were by then enough Muslims in Córdoba to require a large mosque.
Although the Hispano-Visigoths were not forced to convert, conversion whether out of conviction or convenience could have benefits. Ordinary converts normally continued doing what they had done as Christians, working as artisans, shopkeepers, shoemakers, carpenters, labourers etc., but they enjoyed freedom from poll taxes and found it easier to integrate into Muslim society as a whole. From this they derived greater opportunities for advancement, upward mobility, wealth and power.
Visigothic nobles also had a choice. They could chose to remain Christian and negotiate an arrangement with the newcomers, such as the accord between Abd al-Aziz and Theodemir, a Visigothic noble from the region of Murcia in 713. However, Theodemir’s decision to remain Christian incurred the payment of a poll tax and certain penalties (e.g. the requirement of annual quantities of barley, wheat, honey, olive oil). A switch to Islam freed the Muwallad nobles from the obligation imposed on Christians (and Jews), and allowed them to retain authority, only now in the name of the emir in Córdoba and their adopted religion. Nevertheless, the authenticity of their conversion does not appear to have been an issue, neither for the Muwallads or the Arab leaders. What mattered to the former was that they held on to their possessions and enjoyed the privileges of being Muslims. For the Arab leaders, they were ensured of the loyalty of their new co-religionists, although in fact that loyalty was frequently breached.
One of the first and best known Muwallad families, the Banu Qasi, sprang into prominence around the time of Abd al-Rahman I’s death (788), but claimed descent from a Visigothic noble named Cassius. Over time, some of these Muwallads of noble Visigothic origin acquired significant power verging on independence, especially in the outer marches (frontier regions set up especially to defend a boundary) of al-Andalus where direct control from Córdoba was at its weakest. This semi-autonomy called for constant vigilance, and governors loyal to Umayyad regime were frequently dispatched to outer places like Mérida, Toledo, Zaragoza, Badajoz to maintain control. Still, Muwallad rebellions were not unknown, e.g. in the Upper Ebro valley, and in the hinterlands of Badajoz and Mérida, especially in the 9th century when central authority was strained. Sometimes the Muwallads were testing the political waters, sometimes reacting because they felt they were treated as second class Muslims by the Arab elite. For example, during the 9th century, the Banu Qasi family controlled the Upper Ebro valley, whose proximity to Christian lands in the Pyrenees allowed them to play on the rivalries between Córdoba and the Christian kingdoms of Pamplona and Asturias. Another Muwallad, Ibn Marwan, with the help of the Christian king of Asturias, Alfonso III (r. 866-910), rebelled against the emir, Muhammad I (r. 852-86), in 868 and 874 and created his own fiefdom, with Badajoz as his seat of power. The region remained in the hands of his family until 930.
Even proximity to Córdoba was no guarantee of peace from rebellious or disenchanted Muwallads. The most frequently cited case is that of Umar Ibn Hafsun, who carved out for himself a large chunk of south western al-Andalus from his base in the mountainous region surrounding Ronda in the late 9th century. He died undefeated in 917/8, but quarrels amongst his sons allowed Abd al-Rahman III (r 912-961) to regain the land 10 years later.
Although Hispano-Visigothic Christians made up the bulk of the Muwallads, another source of converts was the Saqalibas, slaves of Slavic or Northern and Eastern European origin. Although they first appeared during the rule of al-Hakam I (r. 796-822) and Abd al-Rahman II (r. 822-852), it was during the caliphate of Córdoba (929-1031) that they became prominent. Adopting Islam as their faith, many subsequently joined the caliphate army or entered the civil service, and acquired significant power. Like the disaffected Berbers, the Saqalibas were very much involved in the unrest that marked the last years of the caliphate in the early 11th century. After the fall of Córdoba in 1031, some Saqalibas were sufficiently powerful to become rulers of some of the taifa states that emerged from the break.
Barton, Simon A History of Spain Basingstoke, Hampshire 2004
Carr, Matthew Blood and Faith: The Purging of Muslim Spain New York, London 2009
Collins, Roger Early Medieval Spain: Unity in Diversity 400-1000 Basingstoke, Hampshire 2nd. ed. 1995
Fletcher, Richard Moorish Spain London 1994
Hitchcock, Richard Mozarabs in Medieval and Early Modern Spain Aldershot, Hampshire 2007
Lowney, Chris A Vanished World: Muslims, Christians, and Jews in Medieval Spain Oxford 2005
O’Shea Stephen Sea of Faith: Islam and Christianity in the Medieval Mediterranean World Vancouver, Toronto 2006
Reilly, Bernard The Contest of Christian and Muslim Spain Oxford 1995