By the late tenth century Islam was well established in Spain. Conversions to Islam probably peaked in the tenth century, and it is likely that Muslims formed the great majority of the population of al-Andalus by the year 1000, at which point it extended from the River Duero southwards across the peninsula. At this time al-Andalus found its political expression in the powerful caliphate of Cordoba, but in just over a decade this political unity disintegrated into numerous independent states, the kingdoms (see Chapter 6). Islam in
Spain drew its strength from cities. Each town had its great mosque, the responsibility of the ruler, and numerous smaller local mosques, funded by donations made by the faithful. The fakirs or holy men and the judges who had the duty of preventing blasphemy and heresy were mostly drawn from the urban middle class. Spanish Muslims were staunchly Sunni*: a flowering of ShTism* in the early tenth century in Tunisia found no echo in Spain, and Sunni orthodoxy was also insisted on by the fundamentalist Almoravids and Almohads who arrived from north-western Africa in the late eleventh and the twelfth centuries respectively. Within al-Andalus the three monotheistic faiths of Islam, Judaism, and Christianity coexisted, mostly in cultural isolation from each other, though the fact that c. iioo the legal expert Ibn Abdun thought it necessary to recommend that Muslim women should not enter Christian churches suggests a certain degree of syncretism. Coexistence of faiths in isolation was also a feature of the areas conquered by the Christian kingdoms from the late eleventh century onwards, especially in Valencia and the Balearic Islands, taken over by the kingdom of Aragon in the thirteenth century, which retained significant numbers of Muslim inhabitants (Mudejars), who were allowed to practise their religion and laws, usually in segregated communities.
Religion gave expression to communities, topographically and socially. Each Christian parish would be distinguished by its church, often prominently placed; much more discreetly, each Jewish community would have its synagogue and ritual bath. The rituals that articulated many actions in public life often had a religious basis. By these means religion maintained tradition. At the same time, however, the great population expansion experienced by western Europe in this period necessitated changes in the institutional hierarchies of religion, and in particular the Church acquired a much more legalistic structure than it had had hitherto.