The centrality of Christian ceremonies to daily life for most Europeans meant that those who did not participate were clearly marked as outsiders. Many Muslims left Spain as the Christian “reconquest” proceeded and left Sicily when this became a Christian realm but others converted. In more isolated villages, people simply continued their Muslim rituals and practices, though they might hide this from the local priest or visiting officials.

Islam was geographically limited in medieval Europe, but by the late tenth century, Jews could be found in many areas, often brought in from other areas as clients of rulers to help with finance. Jewish communities could be found in Italian and French cities and in the cities along the Rhine. Jewish dietary laws require meat to be handled in a specific way, so Jews had their own butchers; there were Jewish artisans in many other trades as well. Jews held weekly religious services on Saturday, the Sabbath, and celebrated their own annual cycle of holidays.

Jews could supply other Jews with goods and services, but rulers and city leaders increasingly restricted their trade with Christians to banking and money-lending. This enhanced Christian resentment, as did the ideology of holy war that accompanied the Crusades. Violence against Jews and restrictions on their activities increased further in much of Europe. Jews were expelled from England and later from France. However, Jews continued to live in the independent cities of the Holy Roman Empire and Italy, and some migrated eastward into new towns that were being established in Slavic areas.